Help with a simultaneous equation PLEASE

Hi- I have been struggling with this BBC bitesize grade 8 simultaneous equation!
I know the answers are
x=-4 y=1/2 or x= 5/2 y=-11/4

I really need to understand the steps to get me there as I can’t work out what to do with the
-2xy

This is the question!

Solve the simultaneous equations:
x+2y=-3 x^2-2xy=20

Thank you to anyone who can help!🙏

Just solve using substitution, so rearrange the first to give
y = ...
then sub into the second and solve the quadratic in x.

Thanks! That’s what I’m struggling with!😂
Was hoping for a step by step solution that I could follow!🙄

I’ve had so many attempts! I’m ok with x+2y=-3 but I don’t know how to substitute that into the other equation when it domes to -2xy and then how to get from that to two values for x and y!

I never said I was good at maths!😵*💫

Rearrange the first equation in terms of y so
y = ...
so just like an equation of a line, then replace the y (substitute) in the second equation with the equivalent expression in terrms of x. You should be able to rearrange the first equation and try substituting, so upload what youve tried.