First, rewrite ( 3√z - 1 ) / ( 1 - √z ) by multiplying both the numerator and denominator by -1:
= ( 1 - 3√z ) / ( √z - 1 )
Now, you have:
( 2√z - 3 ) / ( √z - 1 ) - 1 = ( 1 - 3√z ) / ( √z - 1 )
Multiply each term by (1 - √z ) / ( √z - 1 ) - 1
2√z - 3 - 1 · ( √z - 1 ) = 1 - 3√z
2√z - 3 - √z + 1 = 1 - 3√z
√z - 2 = 1 - 3√z
4√z = 3
√z = 3/4
z = 9/16
First, rewrite ( 3√z - 1 ) / ( 1 - √z ) by multiplying both the numerator and denominator by -1:
= ( 1 - 3√z ) / ( √z - 1 )
Now, you have:
( 2√z - 3 ) / ( √z - 1 ) - 1 = ( 1 - 3√z ) / ( √z - 1 )
Multiply each term by (1 - √z ) / ( √z - 1 ) - 1
2√z - 3 - 1 · ( √z - 1 ) = 1 - 3√z
2√z - 3 - √z + 1 = 1 - 3√z
√z - 2 = 1 - 3√z
4√z = 3
√z = 3/4
z = 9/16