Everybody help me solve three math problems, help me solve three math problems

First: Set up a book of x yuan for each book, C book y yuan, and B book (y + yuan.

x+y+(y+

16x+4(y+

The solution gives x= y= y+

Answer: A per dollar, B per dollar, C per dollar.

Second: set x yuan per kilogram of apples and y yuan per kilogram of pears. According to the title.

4x+3y-(3x+2y)=

3x+4y-(3x+2y)=

The solution is x=2, y=

Third: Suppose 1 cow eats x kg per day, 1 horse eats y kg per day, and 1 sheep eats z kg per day.

5x+6y+2z=143

6x+5y+4z=133

3x+2y+z=55

The solution is x=5, y=19, z=2

Finally, there are many problems that cannot be solved without equations, don't always use equations to solve them, and use equations to solve them, the teacher will think you are very good.

10 A plus 10 B plus 10 C equals 115 yuan.

16 A plus 4 B plus 10 C equals yuan.

10 A plus 10 B minus 16 A plus 4 B equals 115 minus yuan.

From this, it can be obtained that 6 B minus 6 A is equal to yuan.

Question 1 is to prove that there are 2 different real roots?

There must be 2 different root factors and disadvantages.

That is, (k+2) renting auspicious staring -4*4*(k-1)=0k-12k+20=0

k = 10 or k = 2

The original equation is the root of real numbers.

1. The master has completed x parts.

So x+30=30 (3 5).

x = 202 x kg of coal burned in March.

Therefore (x = set last year's original plan to produce x million yuan.)

So (9600-x) x

x=8727

Set up x parts after the master, according to the title:

x 30=(1-3 5) (3 5), and the solution is x=20

Coal is burned in March.

x kilograms, according to the title:

SolutionX set up production planned for last year.

x million yuan, according to the title:

9600-x = (1 11)x solution x

1. Equiquantitative relation.

30 total parts completed by the apprentice = 3 5

Solution: The master has completed x parts.

30/(30+x)=3/5

x=202, equivalent relation: coal burned in March - coal burned in March 1 7 = solution: set up a school canteen.

x kg of coal burned in March.

x-x×1/7=

6 7x=x=3, the equivalent relation: last year's original planned output value (1 + 1 11) = 9600 solution: set last year's original planned production of x million yuan.

1+1/11)x=9600

12/11x=9600

x=8800

When a is what the value, the solution of the equation 2 x 1 3a x 1 satisfies 2x 5 = 7 ?

2x 5=7 derives x=1 and substitutes, substituting 2x 1 3a x 1, and a = -1 6

Why is the solution for x+2k 4=11 24—(4—x) 3 x= 3 2?

x=3 2 substitution, k=-23 4

When k is valued, 2 is the equation 3| with respect to xk|Solution of 2x=6x+4?

Substituting x=2 gives k=plus/minus 20 3

Simple substitution,

1.When a=6, there is no solution, and when a is not equal to 6, x=1 a-1 6

2.When a=4, b=-8, innumerable solution, a=4, b is not equal to -8, no solution, a is not equal to 4, b=-8, x=0; A is not equal to 4, b is not equal to -8, x = (b+8) (4-a).

Since I am not very familiar with typing, I will not write the third question, and its mathematical idea is to discuss it by classification.

It's hard, 4 unknowns, 3 equations.

Do you call this solving equations? . Be clear when you ask questions! I think the solution on the 3rd floor is a little bit reliable.