One question is all I need help on.
Hello,y=x²+2xy=3x+20==>x²+2x=3x+20==>x²+2x-3x-20=0==>x²-x-20=0==>x²-21/2x+1/4-20-1/4=0==>(x-1/2)²-81/4=0==>(x-1/2-9/2)(x-1/2+9/2)=0==>(x-5)(x+4)=0==>(x=5 and y= 35 ) or (x=-4 and y=-8)