Answer:
Explanation:
Common factors are the number's , variables found in each of the terms
1) 21x²y = 3 * 7 * x * x * y
35xy² = 5 * 7 * x * y * y
Common factor = 7 * x * y
= 7xy
Answer :(iii) 7xy
2)a² - b² = (a + b)(a - b)
1 - x² = (1 - x) (1 +x)
(ii)
3) x³ - x = x(x² - 1)
= x(x + 1)(x - 1)
Answer: (iv)
4) 225 = 15 * 15 = 15²
x³ - 225x = x(x² - 225)
= x(x² - 15²) {a² - b² =(a + b)(a - b)}
= x(x + 15)(x - 15)
Answer: (ii)
5) 12a²b = 3 * 4 * a * a * b
15ab² = 3 * 5 * a * b * b
Common factor = 3 * a * b = 3ab
12a²b + 15ab² = 3*4*a²*b + 3*5*a*b²
= 3ab (4a + 5b)
Answer:(ii)