Question

evaluate the following by using suitable identities

$304 {}^{2}$
$509 {}^{2}$
$992 {}^{2}$
$799 {}^{2}$
$204 \times 206$

Answer 1

1](300+4)^2 = (a+b)^2=a^2+2ab+b^2=90000 +2400+16=92416

2](500+9)^2=(a+b)^2=a^2+2ab+b^2=250000 +9000+81=259081

3(1000-8)^2=(a-b)^2=a^2-2ab+b^2=1000000-16000+64 =984064

3(800-1)^2= *a-b)^2=a^2-2ab+b^2=640000-1600+1=638401

2](200+4)(200+6)=(x+a)(x+b)=x^2+(a+b)x+ab= 40000+2000+24=42024.