If √ (2x + 2) − √x =1 ,find x.

A.

x = 1 twice

B.

x = 0 or 1

C.

x = 3 or 1

D.

x = 2 twice

Correct answer is A

√(2x + 2 ) − √x = 1

√(2x + 2) = 1 + √x

Square both sides

√(2x + 2)2 = (1 + √x)2

((2x + 2)2)½ = 1 + √x + √x+ x

2x + 2 = 1 + 2√x +x

Collect the like term together

2x − x + 2 − 1 = 2 √x
x + 1 = 2√x

Square both sides

(x + 1)2 = (2√x)2

x2 + 2x + 1 = 4x

x2 + 2x − 4x + 1 = 0

(x2− x)(x + 1)= 0

x(x − 1) −1(x − 1)

(x − 1)(x −1)

Either (x − 1) = 0 or (x − 1) = 0

x = 1 or 1

x = 1 twice