Answer: (x - 1)(x + 1)(x + 7)²
Step-by-step explanation:
x⁴ + 6x² - 7
find two numbers whose product is -7 and sum is +6 --> -1 & 7
Those values go into the parenthesis: (x² - 1)(x + 7)²
Notice that (x² - 1) is the difference of squares --> (x - 1)(x + 1)
