Question

B) Factorize the following using a suitable identity.
i) x?+ 14x + 49
ii) x² + 9x + 20
iii) y + 4y - 21

Answer 1

Answer:

i) x²+ 14x + 49

= x²+7x+7x+49

= x(x+7)+7(x+7)

= (x+7)(x+7)

x²+ 14x + 49 = (x+7)(x+7)

ii) x² + 9x + 20

= x²+5x+4x+20

= x(x+5)+4(x+5)

= (x+4)(x+5)

x² + 9x + 20 = (x+4)(x+5)

iii) y² + 4y - 21

= y²-3y+7y-21

= y(y-3)+7(y-3)

= (y-3)(y+7)

y² + 4y - 21 = (y-3)(y+7)