Answer:
x² - 16
Step-by-step explanation:
Given
(x - 4)(x + 4)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x + 4) - 4(x + 4) ← distribute both parenthesis
= x² + 4x - 4x - 16 ← collect like terms
= x² - 16
72.25 - 51.5= <span>20.75
it is 20.75 feet longer</span>
Answer:
Because 4 is a perfect square
Step-by-step explanation:
When simplifying a radical, you have to look for perfect squares. 4 is a perfect square but x is not. Variables are only perfect squares if they have even numbered exponents so the x has to stay in the radical.