Question

How do you solve for a in `7a - b = 15a`?

Answer 1

`a=-b/8`

Explanation:

Given
`color(white)("XXX")7a-b=15a`

Add `b` to both sides
`color(white)("XXX")7a=15a+b`

Subtract `15a` from both sides
`color(white)("XXX")-8a=b`

Divide both sides by `(-8)`
`color(white)("XXX")a=-b/8`