Answer:
Step-by-step explanation:
by idetity : (a - b)²= a² +b² -2ab
for : (x² - 5)² you have a = x² and b = 5
(x² - 5)²= (x²)²+5² - 2(5)(x²)
(x² - 5)²= x^4+25 -10x²
