Answer:
Step-by-step explanation:
a) (a + b)² = (a + b) * (a +b)
(a + b)³ = (a + b) * (a +b) * (a +b)
a²- b² = (a +b) (a - b)
Here (a + b) is common in all the three expressions
HCF = (a + b)
b) (x - 1) = (x - 1)
x² - 1 = (x - 1) * (x + 1)
(x³ - 1) = (x - 1) (x² + x + 1)
HCF = (x -1)