I don t know how to solve binary equations!! I m in a hurry!!!!!!

Solution: Suppose there are x foreign stamps and y stamps in China, and the requirement is (y-x).As can be seen from the title, x+y=325 (1) y=2x-5 (2) (2) can be converted to 2x-5-y=0

3) (1)+(3) is 3x-5=325, the solution is obtained, x=110 is substituted x=110 into (2), y=215 y-x=115.So Xiao Wang's foreign stamps are 115 fewer than Chinese stamps.

x foreign stamps, y Chinese stamps.

x+y=325

x+2=2y

Solution. x=216

y=109 foreign stamps are 216-109=107 less than Chinese stamps.

Let the Chinese stamps be x, and the foreign stamps are yx+y=325 x-2y=-2 Solution: +Get 3y=327 y=109 Substitute y=109 to get x=216 x-y=216-109=107 Chinese stamps are 107 more than foreign stamps Foreign stamps are 107 less than Chinese stamps (I don't know how to put braces with a keyboard.) The system of equations needs to be bracketed there).

Solution: Xiao Wang's foreign stamps have x sheets, Xiao Wang's Chinese stamps have Y x + y = 3252x-2 = y solution x = 109y = 216 Therefore, Xiao Wang's foreign stamps are less than Chinese stamps: 216-109 = 107 sheets.

If there are x foreign stamps, there are 2x-2 Chinese stamps: x+2x-2=325x=109, then foreign stamps are 2x-2-x=107 less than Chinese stamps.

Solution: Set Xiao Wang's foreign stamps and Chinese stamps have x, Y respectively, then: x+y=325 2x-2=y solution x=109 y=216 y-x=216-109=107.

Set the total amount of property to be n and there are x children destroying the bridge.

then 100+(n-100)*

The solution is n=8100

Each son can share 900 grams of lang.

He had a total of 9 sons.

1) Set group A to produce x limbs a day, and group B to produce y stupid nuclei, then bring hunger digging.

6x=5y300+4x=4y-100

The solution is x=500 and y=600

2) Let the hydrostatic velocity be x, and the water velocity is y, 80=4(x+y)80=5(x-y).

The solution is x=18 and y=2

1.Solution: Let A produce x in one day, and B will produce y.

x+5x=5y 300+4x+100=4y2.Solution: Set the speed of the boat in still water to be x, and the speed against the water is y.

4x=80 5y=80

If an equation contains two unknowns, and the unknowns are both to the power of 1, then the integer equation is called a binary equation with infinite solutions, and if the conditions are added there are finite solutions. In the case of a system of binary equations, there is generally one solution, sometimes no solution, and sometimes an infinite number of solutions. Such as parallelism in a primary function,.

The general form of a binary equation: ax+by+c=0, where a, b are not zero. This is the definition of a binary equation.

Definition of binary linear equations: two linear equations that are combined together and contain two unknowns are called binary linear equations.

So xy-y=8 is not a binary linear equation.

Because a binary equation must have a premise, that is, a formula with two unknowns, such as x+y=10

2x+3y=100

When solving, the basic properties of lighting with x+y=10 are used, and x=10-y is substituted into (10-y)+3y=100

y=45 your xy-y=8 can not be calculated without a prerequisite, the binary equation is to be transformed into a univariate once with a certain basic property to make it, so the equation should be learned and used, but also the definition is well understood, I wish you success in learning.

Take a look at the definition of binary equations in the book == not explained.

xy is quadratic and this equation is binary quadratic.

1. For every increase of $5,000 in the annual rent of each shop, when the annual rent of each shop is set at $130,000 for every additional $5,000 and one less shop is rented out.

130000-100000) 5000 = 6 rooms 2, set the annual rent of each shop is x million yuan, and the unrented shops are y rooms and are not rented out for (x-10), y = 2 (x-10) annual income: (x-1) (30-y)-y*

x-1) (30-2(x-10))-x-10) = 275 simplification 2 x 2-51x + 315 = 0

4x^2-102x+630=0

2x-51/2)^2-(51/2)^2+630=0(2x-51/2)^2=81/4

2x-51 2=+- (plus or minus) 9 2

4x = 51 + 9 or 4x = 51-9

x = 15 or 21 2

Because the shop is rented, x is an integer, so, x=15, y=10 When the annual rent of the shop is positioned at 150,000 yuan, the company's annual income is 2.75 million yuan.

When the annual rent of each shop is set at $00,000, the company's annual income (income, rent, various expenses) is $2.75 million.

Less number of rooms rented: (x-10).

Number of rooms that can be rented: 30-(x-10).

Income, rent, various expenses.

275=x*[30-(x-10)/

275=x*(50-2x)-1*(50-2x)275=50x-2x^2-50+2x-x+102x^2-51x+315=0

2x-21)(x-15)=0

x1=,x2=15

Solution: The annual rent of each room is set at $00,000.

Less rented: (x-10)*10000 5000=2(x-10) rooms rented: 30-2(x-10)=50-2x rooms.

50-2x)x-(50-2x)-2(x-10)*-2x²+50x-50+2x-x+10=2752x²-51x+315=0

2x-21)(x-15)=0

x = or x = 15

A: When the annual rent of each room is set at 10,000 yuan or 150,000 yuan, the annual income is 2.75 million yuan.

When the annual rent of each shop is set at $00,000, the company's annual income is $2,750,000

Unleased quantity: (x-10), x>10, x[30-(x-10), 30x-2x 2+20x-30+2x-20-20-x+10=2752x 2-51x+315=0

2x-21)(x-15)=0

x1 = 21 2 = 10,000 yuan).

or x2 = 15 (10,000 yuan).

x+y=9 x=2 y=772-27=45

The speed is 45 kilometers per hour.

Let the velocity be v and the first time the single digit is x, then the first time you see it is x+10(9-x), the second time you see it is 10x+(9-x), and the third time you see it is 100(9-x)+x

The system of equations can be listed by two journeys.

10x+(9-x)-x-10(9-x)=v100(9-x)+x-10x-(9-x)=3v, simplified to 18x-81=v

891-108x=3v

The solution is v=45

Analyze the topic, the condition is said to be at a constant speed, that is, the distance is proportional to the time, "just over an hour" and "another 3 hours" these conditions are actually telling you the relationship between the driving distance, and the three-hour journey must be three times that of one hour. Then most of the conditions are talking about milestones, which means that we must start with the distance to solve the problem.

It turns out that it is a two-digit sum of 9", so let's not know the number. If the ten digits are x and the single digit is y, then this number is 10x+y. "Just one hour later, he found that the number on the milestone on the side of the road happened to be obtained after the single digit and the ten digit number were reversed for the first time", at this time the number became 10y+x, "After another 3 hours, he found that the number on the milestone was more than 0 in the middle of the two-digit number he saw for the first time" At this time, the number became 100x+y.

All of this is a "translation" of words into mathematical expressions. Here's the equation:

According to the sum of the numbers is 9, list x+y=9

Based on the fact that a three-hour journey must be three times as long as an hour, list 3[(10y+x)-(10x+y)] = (100x+y)-(10y+x).

Simplification yields 27y-27x=99x-9y

3y-3x=11x-y

4y=14x

2y=7x③

It is easy to see from y=7,x=2. The first milestone is 27, the second is 72, the third is 207, and the speed is 72-27 = 45 km/h.

The speed is 45 km/h. Let the number on the tenth digit of the milestone seen for the first time be x, the number on the single digit is y, and the speed is k kilometers per hour, according to the title, there is: (1) x+y=9;（2）（10y+x）-（10x+y）=k*1=k；(3) (100x+y)-(10y+x)=k*3=3k, x=9-y is obtained from (1), x=9-y is brought into (2), (3), (2), (3) two equations, the binary equation of y and k is obtained, and the solution of this equation gives y=7, k=45, so the velocity is 45 km/h.

Solution: Let the first milestone number seen be a ten digit of y and a single digit of x.

So the number on the first milestone is 10y+x, and x+y=9 ......The number on the second milestone is 10x+y

The number on the third milestone is 100y+x

The front and rear velocity v are the same, so the second distance = v 1 = (10x+y)-(10y+x),...

The third distance is =v 3=(100y+x)-(10x+y)....3, get (100y+x)-(10x+y)-3 [10x+y)-(10y+x)]=4v-4v=0

Simplification yields 100y+x-10y-x-4 (10x+y-10y-x)=090y-4 (9x-9y)=0

90y-36x+36y=0

i.e. 126y-36x=0

7y-2x=0 ……

The formula is concatenated into a binary one-dimensional equation, 2+, and 2x+2y+7y-2x=18, that is, 9y=18, y=2, and substituting into the equation, x=7 can be solved, so the velocity v=(10x+y)-(10y+x)=72-27=45

The first time you notice the ten-digit and single-digit numbers on the roadside milestone are x, 9-x, then the cycling speed is.

10 (9-x) + x - [10x + 9-x] = 90-9x - 9x - 9 = 81-18x (kilometers per hour), according to the meaning of the topic 100 x + 9-x = 9x + 9 + 4 (81-18x), 11x + 1 = x + 1 + 4 (9-2x), 18x = 36, x = 2, the speed sought is 45 kilometers per hour.

In the first question d, because the equation is a one-dimensional quadratic equation, the coefficient of the quadratic term cannot be zero.

The second question c, because the constant coefficient term is zero, so m 2-4 = 0, but the equation is a one-dimensional quadratic equation, so the coefficient of the quadratic term is not zero, so m cannot = 2, so m = -2

Get ax 2+a-2ax=2x 2-2

Sorted out ax 2+2x 2-2ax+a+2=0ax 2+2x 2 is not equal to 0, so x is not 2

2b。Constant terms m2-4 = 0, m 2 = 4, m = -2 or 2

The first question is d, and the equation is ax 2-2ax+a=2x 2-2, which is a quadratic equation, and the quadratic coefficient is not 0, so a is not equal to 2

The second question is c, the constant term is m 2-4, which is zero, m = plus or minus two, but the coefficient of the quadratic term is not equal to 0, that is, m-2 is not equal to 0, so m = -2

Let the cost price be x

According to the title, x(1+50%)=450

Solution x=300 yuan.

And with eight folds, you can get **** as the yuan.

Therefore, the profit is 360-300 = 60 yuan.

If the original price of the commodity is x, then x(1+50%)=450, and x=3008 discount**.

So 360-300 = 60, that is, the profit is 60 yuan.

Happy learning

Set the cost price of a yuan.

50%a+a=450

a=450 divided by 150%=300 yuan=original price.

450 times 80% = 360 yuan.

360-300=60=Original price-current price=Profit.