Question

use suitable idenity to solve 1 ) 98^2 (2) 102^2

Answer 1

1) (98)^2 = 9604 2) (102)^2 = 10404 .

Answer 2

$1)98 {}^{2}$

$= (100 - 2) {}^{2} \\ = 100 {}^{2} - 2(100 \times 2 + 2 {}^{2}$

$10000 - 400 + 2$

$6000 + 2 \\ = 6002$

$2)102 {}^{2}$

$(100 - 2 ){}^{2} \\ 100 {}^{2} - 2(100 \times 2) + 2 {}^{2}$

$10000 - 400 + 4 \\ = 10000 + 404$

$99596$