(x+5)^2-5x(2-x)=x^2+10x+25-10x+5x^2=6x^2+25
16y+2(y-4)^2=16y+2y^2-16y+32=2y^2+32
(2a-1)^2=4a^2-4a+1
(x+3y)^2=x^2+6yx+9y^2
(7-x)(7+x)=49-x^2
(x+5)^2-5x(2-x)=x^2+10x+25-10x+5x^2=6x^2+25
16y+2(y-4)^2=16y+2y^2-16y+32=2y^2+32
(2a-1)^2=4a^2-4a+1
(x+3y)^2=x^2+6yx+9y^2
(7-x)(7+x)=49-x^2