Question

How to solve -2(-4f+5)=-7+2f-9

Answer 1

`f=(3)/(5)`

Explanation:

`-2(4f+5)=-7+2f-9`

First, use PEMDAS to distribute the -2 to the parenthesis.

`-8f -10 = -7+2f -9`

Combine like terms on the right side.

`-8f - 10 = -16+2f`

Now, you may either subtract the f's or the constants. I'll subtract the constants first, meaning I will add 10 to both sides.

`-8f = -6 + 2f`

Now subtract the 2f from both sides.

`-10f = -6`

Divide both sides by 10.

`f = (-6)/(-10)`

Simplify.

`f = (3)/(5)`

Answer 2

The value of f:

• 
  `f=-1`

Explanation:

Given the expression

`-2\left(-4f+5\right)=-7+2f-9`

Group like terms

`-2\left(-4f+5\right)=2f-7-9`

Subtract the numbers: -7-9=-16

`-2\left(-4f+5\right)=2f-16`

Expand: -2(-4f + 5) = 8f - 10

`8f-10=2f-16`

Add 10 to both sides

`8f-10+10=2f-16+10`

Simplify

`8f=2f-6`

Subtract 2f from both sides

`8f-2f=2f-6-2f`

Simplify

`6f=-6`

Divide both sides by 6

`(6f)/(6)=(-6)/(6)`

Simplify

`f=-1`

Therefore, the value of f:

• 
  `f=-1`