x² + 4x = 96
Subtract 96 from both sides to get the equation equal to zero:
x² + 4x - 96 = 0
We can solve for x either by factoring or by using the Quadratic Formula. Let's attempt to factor first. To factor, find two numbers whose sum is 4 and whose product is -96. Since 96 is negative, the pair will be one positive and one negative (a positive times a negative is always negative). Let's start listing addends of 4 and calculating their product.
12 + (-8) = 4; 12 × (-8) = -96
The pair is 12 and -8. The factored polynomial is (x + 12)(x - 8). To find x, find the zeros.
x + 12 = 0
x = -12
x - 8 = 0
x = 8
Answer:
x = -12 and x = 8