Question

Q2. Factorise by using Identities:
4a² + 9b² + 12ab
16x²y² + 1 – 8xy
9x² - 16 y²
4x² - a² + 2a -1
z² + 1/z2 + 2

Answer 1

Correct option is

C

(2a+3b−4c)

2

Given:

4a

2

+9b

2

+16c

2

+12ab−24bc−16ac

Use the formula:

(a+b+c)

2

=a

2

+b

2

+c

2

+2ab+2bc+2ca

Simplify the equation.

4a

2

+9b

2

+16c

2

+12ab−24bc−16ac=(2a)

2

+(3b)

2

+(−4c)

2

+2×2×3ab+2×(−4)×3bc+2×(−4)×2ac

=(2a+3b−4c)

2

Thus, the factor of the equation is (2a+3b−4c)

2

.