Question

Solve x^2 - 4 = 77.

Answer 1

Answer:

X = 9 or x = -9

Step-by-step explanation:

We want to solve the quadratic equation

${x}^{2} - 4 = 77$

We shall use the square root method

Let us add 4 to both sides to get:

${x}^{2} - 4 + 4 = 77 + 4$

${x}^{2} = 81$

We take square to get:

$x = \pm \sqrt{81}$

$x = \pm9$

The solution is x=9 or -9