Question

7. -5a + 7 = -38
Please show your work

Answer 1

-5a +7 =-38

-5a +7 (-7) = -38 (-7)

-5a= -45

-5a (÷-5)= -45 (÷-5)

a= 9

Answer 2

`\boxed{\tt a=9}`

Explanation:

We are given the equation:

`-5a+7= -38`

We want to solve for a, so we must isolate a on one side of the equation.

7 is being added to -5a. The inverse of addition is subtraction. Subtract 7 from both sides of the equation.

`-5a+7-7=-38-7`

`-5a=-38-7`

`-5a=-45`

a is being multiplied by -5. The inverse of multiplication is division. Divide both sides of the equation by -5.

`(-5a)/(-5) =(-45)/(-5)`

`a=(-45)/(-5)`

`a=9`

Let's check our solution. Plug 9 in for a.

`-5a+7=-38`

`-5(9)+7=-38`

`-45+7=-38`

`-38=-38`

This checks out, so we know our solution a=9 is correct.