Question

How do you solve `-4(-d-4)=-4d+6(2d+6)`?

Answer 1

`d=-5`

Explanation:

The first step is to distribute brackets on both sides of the equation.

`rArr4d+16=-4d+12d+36`

simplifying right side.

`4d+16=8d+36`

Collect terms in d, on the left side and numeric values on the right.

subtract 8d from both sides.

`4d-8d+16=cancel(8d)cancel(-8d)+36`

`rArr-4d+16=36`

subtract 16 from both sides.

`-4dcancel(+16)cancel(-16)=36-16`

`rArr-4d=20`

To solve for d, divide both sides by - 4

`(cancel(-4) d)/cancel(-4)=20/(-4)`

`rArrd=-5`

`color(blue)"As a check"`

`"left side " =-4(-(-5)-4)=-4xx1=-4`

`"right side " =(-4xx-5)+6(2xx(-5)+6)`

`=20+6(-10+6)=20+6(-4)=20-24=-4`

`"Thus both sides " =-4`

`rArrd=-5" is the solution"`