Question

Решите ребят!система:3y+5x=29,y+7x=31;способом подстановки!

Answer 1

3y+5x=29

y+7x=31

 

3y+5x=29

x=-0.6y+5.8

 

y+7x=31

y+7*(-0.6y+5.8)=31

y-4.2y+40.6-31=0

-3.2y+9.6=0

y=9.6/3.2

y=3

 

3y+5x=29

3*3+5x=29

-20+5x=0

x=20/5

x=4

Answer 2

Problem Statement

We are given the following system of equations: ``` 3y + 5x = 29 y + 7x = 31 ``` We need to solve this system using the method of substitution.

Solution

To solve the system of equations using the method of substitution, we'll solve one equation for one variable and substitute it into the other equation.

Let's solve the second equation for y: ``` y + 7x = 31 y = 31 - 7x ``` Now we'll substitute this expression for y into the first equation: ``` 3(31 - 7x) + 5x = 29 93 - 21x + 5x = 29 -16x = -64 x = 4 ``` Substituting the value of x back into the second equation, we can find the value of y: ``` y + 7(4) = 31 y + 28 = 31 y = 3 ```

Therefore, the solution to the system of equations is x = 4 and y = 3.