Question

Solve by identity - a²- b² = (a+b)(a-b)
1) 51² - 49²
2) (1.02)² - (0.98)²

Answer 1

1) (51-49) (51+49)

(2). ( 100)

200 ans

Answer 2

$\large{\sf{\underline{\underline\red{Solution!!}}}}$

$1)\:\:\sf{51^2-49^2}$

$:\implies\:\sf{(a+b)(a-b)=a^2-b^2}$

Here,

a = 51  , b = 49

Now,

$:\implies\:\sf{(51+49)(51-49)}$

$:\implies\:\sf{100\times2}$

$:\implies\:\sf{200}$

$2)\:\:\sf{(1.02)^2-(0.98)^2}$

$:\implies\:\sf{(a+b)(a-b)=a^2-b^2}$

Here,

a = 1.02²  , b = 0.98²

Now,

$:\implies\:\sf{(1.02+0.98)(1.02-0.98)}$

$:\implies\:\sf{2\times 0.04}$

$:\implies\:\sf {0.08}$