Question

Solve using suitable identities-

a) (x + 3) (x – 4)

b) (a + 3b – 4c )2​

Answer 1

Answer:

a) x^2 - x - 12

b) 2a + 6b - 8c

Step-by-step explanation:

a) (x+3)(x-4)

Using identity:- (x+a)(x-b) = x^2 + (a-b)x - ab

so a=3

and b= 4

so x^2 + (3-4)x - (3)(4)

ans x^2-x-12

b) (a+3 b - 4 c)2

Using identity:- x(A+B+C) = xA + xB + xC

where A= a

B=3b

C= -4c

x = 2

2(a) + 2(3b) + 2(-4c)

ans=2a + 6b - 8c