My problem is multiply

4xy3 - 2x2y - 5xy2
I worked it out like this
4*2*5 =40
x*x*x= x3
x³ *y*y² =y^6
answer is 40x³ y^6
Is this correct?

yes.

thank you

Yes, your solution is correct! Great job!

To explain step by step, you need to multiply the coefficients (numbers) and the variables separately.

Step 1: Multiply the coefficients:
4 * 2 * 5 = 40

Step 2: Multiply the x-variables:
x * x * x = x^3

Step 3: Multiply the y-variables:
y^3 * y^2 = y^(3+2) = y^5

Now, put it all together:
40x^3y^5

So, your final answer is indeed 40x^3y^5. Well done!