How do I simplify by combining these numbers - 3x - 5y + 2x + 10y

Combine - 3 and 2 so id be - x and combine - 5 and 10 so id be 5y so the answer would be - x + 5y

They are basically like groups. Take - 3x+2x, Just do - 3 + 2 = - 1 and then just add the x. So - 1x. Next you have - 5y+10y. Just do - 5 + 10 = 5 and remember to add the x on so your final answer should be - 1x + 5y