Expand the brackets in the following expression

(5y-3)^2

My answer is 5y^2-3^2
The answer i worked out seems to simple but is it correct? If not can someone tell me what i need to do. thanks

You have not multiplied out the brackets

(5y-3)^2 =(5y-3)(5y-3)

(5y-3)(5y-3)= (5y)^2-(2.3.5y)+3^2

(5y)^2-(2.3.5y)+3^2 = 25y^2-30y+9