A few math problems, the equation master is advanced, okay to give points!

1.Set the time to x according to the title.

30/2x/30-30/2x/60=15

x=6060min=1h1h*30km=30km2Set the E model printer to buy x units according to the title.

1000x+(30-x)2000=50000 1000x+(30-x)1700=50000

x=10 x= 10 7 (rounded).

So x=10

1 solution: Set up a small Zhang's house and the railway station 2x kilometers apart.

According to the title, x 30-x 60=15 60

The solution is x=15

2x=30A: Xiaozhang's house and the railway station are 30 kilometers apart.

Can a kind of printer be 17 yuan, it may be 1700 yuan, if it is calculated according to 1700 yuan, the process is as follows, for reference:

If A is X, B, and B, then the E model printer is bought (30-x-y).

According to the title, 2000x+1700y+1000(30-x-y)=50000

Simplify to get x+16y=20

When y=0, x=20, 30-x-y=10

When y=1, x=4, 30-x-y=15

A: When I bought 20 units of type A, I bought 10 units of model E printer.

When I bought 4 units of type A and 1 unit of type B, I bought 15 units of model E printers.

Set up a distance of x kilometers between Xiao Zhang's house and the railway station, which is obtained by the title.

15 minutes = 1 4 hours = hours.

Taxi = 2 * 30 = 60km hours.

Calculated by time).

1/2x÷60+

1/120x=

x=30km

2, is your title not written correctly enough, b is only 17??

Each person is allowed to carry a kilogram of luggage free of charge.

150-a）/（150-3a）＝8/4

a 30 kg.

Solution: Let each person bring x kg for free, and the equation is: (150-x) 8=(150-3x) 4

600-4x=1200-24x，20x=600，x=30.

A: Each person can carry 30 kg of luggage free of charge.

If each person can bring xkg for free, the excess will be charged 150-x=8k per yuan ykg, 150-3x=4k will be x=60 Thank you!

It is easy to understand with arithmetic.

1.Speed is inversely proportional to time, assuming that the original speed at the time of departure is 1, and the speed after the accident is 7 10, the time taken for this journey is the original 10 7, and the time used for this journey is 10 7 = 3 7, and the actual time taken for this journey = 2 (3 7) = 14 3 (hours).

2.If you go another 21 kilometers from the original speed in the event of an accident, the corresponding time for the next leg of the journey is 1 (3 7) = 7 3 (hours), so the time taken for 21 kilometers = 14 3-7 3 = 7 3 (hours).

3.Original speed = 21 (7 3) = 9 (km/h) 4Camp distance of A and B = 9 * (4 + 14 3) = 78 (km) Equation: Solution: Let the distance velocity be 10x and the time is t10xt=40x+7x(t+2-4).

t=26/3

7x(t-2)=10x*21/10x+(t-3-21/10x)*7xx=9/10

So, the distance is 10*9 10*26 3=78 km, thank you.

1.Set the original price of the product to be $x.

1 + 20%)x = 300

x = 300 ÷

x = 250

A: The original price is 250 yuan.

2.Last year, the average monthly production of machine tools x sets.

3x + 6 = 180

3x = 180 - 6

3x = 174

x = 174 ÷ 3

x = 58

A: Last year, an average of 58 machine tools were produced per month.

3.The younger brother is x years old this year.

2x - 3(x - 4) =4

2x - 3x + 12 = 4

x = 4 - 12

x = 8x = 8

8 2 = 16 years old.

A: My sister is 16 years old.

1.Solution: Let the original price of the product be X yuan.

1+20%）x=300

x=2502.Solution: Last year, the average monthly production of machine tools x.

3x+6=180

x=583.Solution: Let's say my sister is x years old this year.

x-4）/3=x/2-4

x=16

1. Set the original price x

1+20%）x=300，x=250

2. Set up an average monthly production of x machine tools last year.

3x+6=180，x=58

3. Set this year's sister x years old.

3*（x/2-4）=x-4，x=16

1. The question is incomplete, if the number of books in each set is the same, then x=8 books.

x+5=100 x=19

x+x/4=66 x=8

Solution: Set the fast horse x days to catch up with the slow horse.

150×(12+x)=240x

1800+150x=240x

240x-150x=1800

90x=1800

x=20A: Fast horses can catch up with slow horses in 20 days.

Suppose a few days to catch up as x can get the equation as follows.

240x=150（12+x）

x=20

Establish; Fast horses x days catch up with slow horses.

12x150=240(12+x)

1800=2880+240x

1080=240x

Answer; Fast horses catch up with slow horses.

1.Solution: 3000*(1+RMB.)

2. Solution: 5000*(1+RMB.)

3. Solution: Yuan.

4. Solution: 800 * 17% = 1.36 million yuan.

5. Solution: 54 boys (1 + 80%) = 30 people, 54-30 = 24 girls 6, solution: 480 (1 + 20%) + 480 = 880 trees.

Eun, I'll help you out. (* is a multiplication sign is a division sign).

5 Male: 54*5/9, Female: 54*4/96 480+480 (120%)

+3000*

5. Boys: 54 (1+80%)

Female: 54 (1+80%)*80%.

Note: In the formula, "is the divide sign" and "* is the multiplication sign".

1.(3000*3* No interest is paid on the principal, so it is the money of interest multiplied by 2 of the tax rate.)（5000*3*

5.Boys 54 (1+80%) Girls 54-Boys Boys 30 Girls Grade 24 480 (1+20 )=400 A total of 400+480=880

1 question: 3000+3000 2 question: 5000+5000 3 question: 4 question: 800 17 =? 10,000 yuan

5 Questions: (1) Male students; 54 (1+80)=30 Female: 30 80 6 questions: 480+480 (1+20).

(1) If.

6x^(2m-3)-(n-2)x^2=3

is a one-dimensional equation about x, finding the values of m and n.

Solution: The 2nd power coefficient of x is 0, ie.

n-2=0 gives n=2

The exponent of 6x (2m-3) is 1, that is, 2m-3=1, and the equation about x is solved when m=2(2)k is taken as an integer:

k(x+1)=k-2(x-2)

Is the solution an integer?

Solution: k(x+1)=k-2(x-2).

kx+k=k-2x+4

2x+kx=4

2+k）x=4

x=4 (2+k), i.e., as long as 4 (2+k) is an integer, the solution of x is the integer 2+k=4, or 2+k=1, 2+k=-4, 2+k=-1, so, k=2, or k=-1, k=-6, k=-3, k(x+1)=k-2(x-2).

Is the solution an integer?

(1) Derived from the title.

2m-3=1 n-2=0

The solution yields m=2 and n=2

2) k(x+1)=k-2(x-2), and (k+2)x=4, i.e., x=4 (k+2).

From the solution of the equation as an integer, the value of k is -6,-4,-3,-1,0,2, I hope it will help you, remember to adopt it!!

Solve equation (1) to get x=4 because the two equations have the same solution, so bring x=4 into equation (2) to get the value a.

Solve the first equation x=4 first, and then bring in the second equation to solve a=-15 4.