Question

what is formula of (a+b)

Answer 1

if you meant (a+b)^2 then the formula is a^2 +2ab+b^2

Answer 2

$(a + b)^2 = a^2 + 2ab + b^2 \\ \\ (a + b) ^3 = a^3 + 3a^2b + 3ab^2 + b^3$