Question

Using identity find (100+4) (100-7)

Answer 1

(x+a)(x+b)=x²+(a+b)x+ab
=100²+(4+(-7))100+(4×(-7))
=10000-300-28
=9672

Answer 2

(100+4)(100-7)
Using formula :- (x+a)(x+b) = x²+(a+b)x+ab
=> (100)²+ (4-7)100 + 4×(-7)
=> 10000 - 300 - 28
=> 9700-28 = 9672
Verify :- (100+4)(100-7) = 104×93 = 9672