Question

find the square of 40s using the identity a + b whole square is equal to a square + b square plus 2 ab​

Answer 1

Answer:

1600

Step-by-step explanation:

40 can be written as 30+10

$(a+b)^{2} =a^{2} +2ab+b^{2}\\(30+10)^{2} =30^{2}+2*30*10+10^{2}$

               $=900+600+100\\=1600$