Question

How do you solve `\frac { 4} { d + 8} = \frac { 7} { d - 18}`?

Answer 1

`d=-(128)/(3)~=-42.667`

Explanation:

We multiply in both sides by `(d+8)(d-18)` so we end up with:
`(d-18)4=7(d+8)`

we multiply,
`4d-72=7d+56`

we isolate `d`,
`4d-7d=56+72`

`-3d=128`

`d=-(128)/(3)`