4x+30-2x^2=0 i dont know how to do this

Undistribute the -2
-2(x^2-2x-15)=0
factor
what2 numbres multlpy to get -15 and add to get -2
-5 and 3
-2(x-5)(x+3)=0
set to zero

x-5=0
x=5

x+3=0
x=-3

x=-3 or 5

Whats your question