Question

if x=2; a=1; b=3 then verify the identity (x+a)(x+b)=x2+(a+b)x+ab​

Answer 1

Step-by-step explanation:

Given -

x = 2

a = 1

b = 3

To show -

(x + a)(x + b) = x² + (a + b)x + ab

Now,

(2 + 1)(2 + 3) = (2)² + (1 + 3)2 + 1×3

= 3×5 = 4 + 8 + 3

= 15 = 15

LHS = RHS

Hence,

Proved..

Some related formulas -

• (a + b)² = a² + 2ab + b²
• (a - b)² = a² - 2ab + b²
• (a + b)(a - b) = a² - b²
• (a + b)³ = a³ + 3a²b + 3b²a + b³
• (a - b)³ = a³ - 3a²b + 3b²a - b³

Answer 2

$\huge\mathfrak\blue{Answer:}$

Given:

x=2

a=1

b=3

To Verify:

We need to verify the identity (x+a) (x+b) = x^2+ (a+b)x + ab.

Solution:

(x+a) (x+b) = x^2+ (a+b)x + ab _____(1)

Substituting the given values in equation 1 we have,

(2 + 1) (2 + 3) = 2^2 + (1 + 3) × 2 + 1×3

(3) × (5) = 4 + (4) × 2 + 3

15 = 4 + 8 + 3

15 = 12 + 3

15 = 15

Therefore LHS = RHS

Hence verified!!