Question

Factorise: a(a - 1) - b(b - 1)

Answer 1

Answer:

Multiplication

Step-by-step explanation:

a(a - 1) - b(b - 1)

a²-a-b²+b

Answer 2

Answer:

(a-b)(a+b-1)

Step-by-step explanation:

a(a-1) -b(b - 1)

a² - a -b² + b

(a² -b²) -a + b

(a² -b²) -(a-b)

(a -b)(a+b) - (a - b)

(a -b)(a + b - 1) {we take a - b common}