Evaluate 55times 45 using suitable identity-

Question

Toppr Admin · Accepted Answer

Using Formula -x-a-x-b- - x2-a-b-x-ab-Writing 55-xA0-as-xA0-50-5 and 45-xA0-as-xA0-50-x2212-5-xA0-x21D2- -50-5-50-x2212-5- - 502-5-x2212-5-50-5-x2212-5- 2500-0-50-x2212-25- 2475-The answer is 2475

Evaluate $55 \times 45$ using suitable identity.

Using Formula $(x + a) (x + b)$ = $x^{2} + (a + b) x + a b$
Writing $55 a s 50 + 5$ and $45 a s 50 - 5$
$\Rightarrow$ $(50 + 5) (50 - 5)$ = $50^{2} + [5 + (- 5)] 50 + (5) (- 5)$
$=$ $2500 + (0) 50 - 25$
$=$ $2475$
The answer is $2475$

Evaluate 55×45 using suitable identity.

Using Formula (x+a)(x+b) = x2+(a+b)x+ab Writing 55 as 50+5 and 45 as 50−5 ⇒ (50+5)(50−5) = 502+[5+(−5)]50+(5)(−5) = 2500+(0)50−25 = 2475 The answer is 2475

Evaluate $55 \times 45$ using suitable identity.

Using Formula $(x + a) (x + b)$ = $x^{2} + (a + b) x + a b$
Writing $55 a s 50 + 5$ and $45 a s 50 - 5$
$\Rightarrow$ $(50 + 5) (50 - 5)$ = $50^{2} + [5 + (- 5)] 50 + (5) (- 5)$
$=$ $2500 + (0) 50 - 25$
$=$ $2475$
The answer is $2475$