Question

Evaluate 105 × 108 without multiplying directly.

Answer 1

105 × 108 = 11340

Given :

The expression 105 × 108

To find :

The value of the expression without multiplying directly.

Formula :

(x + a)(x + b)=x² + (a + b)x + ab

Solution :

Step 1 of 2 :

Write down the given expression

The given expression is 105 × 108

Step 2 of 2 :

Simplify the given expression

The given expression

$\sf = 105 \times 108$

$\sf = (100 + 5) \times( 100 + 8)$

We use the formula

(x + a)(x + b)=x² + (a + b)x + ab

We take x = 100 , a = 5 , b = 8

Thus we get

$\sf 105 \times 108$

$\sf = (100 + 5) \times( 100 + 8)$

$\sf = {100}^{2} + (5 + 8) \times 100 + (5 \times 8)$

$\sf = 10000 +(13 \times 100) + 40$

$\sf = 10000 +1300 + 40$

$\sf = 11340$

Answer 2

Answer:

105×108

Step-by-step explanation:

»(100+5) (100+8)

»[100×5] [100×8] [100×100] [5×8]

»[10000 +800+500+40]

» (10800+540)

»(11340)

Hence the answer is (11340)