Question

How to solve this problem?

2x+y=3
-2+5y=-9

Answer 1

`x=11/5 and y =(-7)/5`

Explanation:

`2x + y = 3`
`-2 + 5y = -9`

This is called a system of equations!

To solve this system of equations, we gonna use the substitution method.

So, we wanna solve `5y - 2 = -9` for `y`

`5y - 2 = -9`

Start by adding `2` on both sides

`5y - 2 + 2 = -9 + 2`

`5y = -7`

Then divide both sides by `5`

`(cancel5y)/cancel5 = (-7)/5`

`y=(-7)/5`

Now we wanna use the value of `y` to find the value of `x`.

We gonna do that by substitute `(-7)/5` for `y` in `2x + y=3`
What does that mean? It means that we gonna replace `y` by `(-7)/5` in the equation.

`2x + y = 3`

#2x + (-7)/5 = 3

Now we can add `7/5` to both sides

`2x + (-7)/5 + 7/5=3 + 7/5`

`2x = (15 + 7)/5`

`2x = 22/5`

Divide both sides by `2`

`(cancel2x)/cancel2 = 22/(5/2)`

`x = 11/5`

Thus,

The answers are: `x=11/5 and y=(-7)/5`