Question

How do you solve `\frac { 6} { a+ 18} = \frac { 2} { 5}`?

Answer 1

`frac{6}{a+18}=2/5`

Cross multiply:
`(2)(a+18)=(5)(6)`

Divide each side by 2:
`a+18=(5*6)/2`
`a+18=15`

Subtract 18 from each side:
`a=-3`