4x2 - 1 = 15

find the justification

see below

Step-by-step explanation:

4x^2 - 1 = 15

Add 1 to each side using the addition property of equality

4x^2 - 1+1 = 15+1

4x^2 = 16

Divide each side by 4 using the division property of equality

4x^2/4 = 16/4

x^2 = 4

Take the square root of each side

sqrt (x^2) = ±sqrt (4) property of square roots

x = ±2