Do you want us to answer or simplify?
Simplify:=−18x^7 y^3 + 21x^5 y^4+ 15x^2 y^5
See, please, suggested decision:
When the line intersects the xy-plane, then parameter z=0, when does the xz - y=0 and when does yz, x=0. All the details are in attachment.
If it's possible, check arithmetic part.
The answer is 1.A 2.B ( I think) 3.B 4.B
(Root symbol) and under that 3x. And then outside of the root symbol -2x