Evaluate 102times 98 using suitable standard identity-

Question

Toppr Admin · Accepted Answer

Using the identity -x-a-x-b- - x2-a-b-x-ab-Writing 102 as 100-2 and 98 as 100-x2212-2Hence -100-2-100-x2212-2- - 1002-2-x2212-2-100-2-x2212-2- 10000-0-100-x2212-4- 9996 The answer is 9996

Evaluate $102 \times 98$ using suitable standard identity.

Using the identity $(x + a) (x + b)$ = $x^{2} + (a + b) x + a b$
Writing $102$ as $100 + 2$ and $98$ as $100 - 2$
Hence $(100 + 2) (100 - 2)$ = $100^{2} + [2 + (- 2)] 100 + (2) (- 2)$
$=$ $10000 + (0) 100 - 4$
$=$ $9996$
The answer is $9996$

Evaluate 102×98 using suitable standard identity.

Using the identity (x+a)(x+b) = x2+(a+b)x+ab Writing 102 as 100+2 and 98 as 100−2Hence (100+2)(100−2) = 1002+[2+(−2)]100+(2)(−2) = 10000+(0)100−4 = 9996 The answer is 9996

Evaluate $102 \times 98$ using suitable standard identity.

Using the identity $(x + a) (x + b)$ = $x^{2} + (a + b) x + a b$
Writing $102$ as $100 + 2$ and $98$ as $100 - 2$
Hence $(100 + 2) (100 - 2)$ = $100^{2} + [2 + (- 2)] 100 + (2) (- 2)$
$=$ $10000 + (0) 100 - 4$
$=$ $9996$
The answer is $9996$