Question

Find the LCM and HCF of
(a) x² + 2x –15 and 3x² - 11x+6​

Answer 1

x² + 2x - 15

☛ x² + 5x - 3x - 15

☛ x(x + 5) - 3(x + 5)

☛ (x + 5)(x - 3)

➜ x² + 2x - 15 = (x + 5)(x - 3)

3x² - 11x + 6

☛ 3x² - 9x - 2x + 6

☛ 3x( x - 3) - 2(x - 3)

☛ (x - 3)(3x - 2)

➜ 3x² - 11x + 6 = (3x - 2)(x - 3)

HCF = product of common terms with lowest power

✪ HCF = (x - 3)

LCM = product of prime factors with highest power

☛ (x + 5)(x - 3)(3x - 2)

☛ (x + 5)(3x² - 11x + 6)

☛ 3x³ - 11x² + 6x + 15x² - 55x + 30

☛ 3x³ + 4x² - 49x + 30

✪ LCM = 3x³ + 4x² - 49x + 30

Answer 2

I hope it's help for you