Question

204 × 207 by using identity
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Answer 1

(200+4)(200+7)=40000+1400+800+28

42228

Answer 2

204×207

(200+4)×(200+7)

on using identity

(x+a)(x+b)=x^2+(a+b)x+ab

here x =200 ,a=4 ,b=7

(200)^2+(4+7)200+(4*7)

40000+(11)200+11

40000+2200+11

42211 is the answer