Question

expand (3x - 1/2y) (3x + 1/2y)​

Answer 1

(a-b)(a+b)=a²-b²

(3x)²-(1/2y)²

9x²-1/4y²

Answer 2

(3x - 1/2y) (3x + 1/2y)

(3x)^2 - (1/2y)^2

9x^2 - 1/4y^2

identity used : (a-b)(a+b)=a^2- b^2

^ means raised to the power o