16x^2-15-21=0

Solution for 16x^2-15-21=0 equation:

Simplifying
16x2 + -15 + -21 = 0

Reorder the terms:
-15 + -21 + 16x2 = 0

Combine like terms: -15 + -21 = -36
-36 + 16x2 = 0

Solving
-36 + 16x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '36' to each side of the equation.
-36 + 36 + 16x2 = 0 + 36

Combine like terms: -36 + 36 = 0
0 + 16x2 = 0 + 36
16x2 = 0 + 36

Combine like terms: 0 + 36 = 36
16x2 = 36

Divide each side by '16'.
x2 = 2.25

Simplifying
x2 = 2.25

Take the square root of each side:
x = {-1.5, 1.5}