Question

find the square 78 using long identity​

Answer 1

Answer:

(78)^2=

(80-2)^2

we know that (a-b)^2=a^2-2ab+b^2

Similarly,

(80)^2-2*80*2+(2)^2

80*80-2*80*2+2*2

6400-320+4

6404-320=

6084

Ans=6084