`1/2x=-15`

To solve an equation we must get an answer for x. Therefore multiply both sides by 2 which can be written as `2/1` if it is confusing with fractions:

`2/1 times 1/2 x = -15 times 2`

`therefore x=-30`

To check your answer, substitute the value for x into the original equation. Due to the fraction -30 can be written as `(-30)/1` :

`1/2times (-30)/1 = -15`

`(-30)/2 = -15`

-15 = -15

`therefore` **x=-30**

Treat the second equation the same way by multiplying by the denominator (5) and solve. eNotes rules do not allow me to answer multiple questions. Or you can post the second one separately.