Question

If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the first equation is substituted into the second equation.

8x − y = −9
4x − 3y = −22

Answer 1

8x - y = -9
8x + 9 = y...so we sub in 8x + 9 for y in the 2nd equation

4x - 3y = -22
4x - 3(8x + 9) = -22 <===

Answer 2

-20x -27 is the required expression.

Explanation:

whenever we are to solve the system of equations by substitution method we have to write one variable in the form of other so as to get the value of unknowns

here, we are given two expressions:

`8x-y=-9`

And
`4x-3y=-22`

We have to substitute x in terms of y because the equation should be equivalent to y we will put
`y=8x+9` in
`4x-3y=-22`

we will get:

`4x-3(8x+9)`

`\Rightarrow 4x-24x-27`

`\Rightarrow -20x-27` is the expression we will get after expression equivalent to y.