Question

Solve the following quadratic equation by applying square roots y=-2x^2+ 128

Answer 1

Given the equation:

$\text{ y = -2x}^2\text{ + 128}$

In solving the quadratic equation by applying square roots, let's only focus at -2x^2 + 128 and disregard y, then we find x by generating this:

$-2x^2\text{ + }128\text{ = 0}$$-2x^2\text{ = -128 }\rightarrow x^2\text{ = }\frac{128}{2}$$\text{ x}^2\text{ = 64 }\rightarrow\text{ x = }\sqrt[]{64}$$\text{ x = }\pm\text{ 8}$

Therefore, the answer is letter D.