How do you solve \frac { 2} { z + 1} = \frac { 1} { z - 8}?

1 Answer
Apr 3, 2017

Multiply both sides by the least common denominator and solve for z.

z = 17

Explanation:

To solve the problem it is helpful to remove the denominators.

To do this multiple both sides by the LCM of the denominators.

The LCM is (z + 1)( z - 8 )

cancel(( z + 1))( z -8) xx 2 / cancel((z +1)) = ( z+ 1)(cancel( z -8)) xx 1 /cancel(( z-8))

Multiplying this out removes the denominators. which results in:

( z -8) xx 2 = (z + 1) xx 1 " " removing the parentheses results in

2z - 16 = z + 1" " add 16 to both sides of the equation

2z -16 + 16 = z + 1 +16

2z = z + 17" " Subtract 1z from both sides to isolate z

2z- 1z = 1z - 1z + 17 This gives

z = 17