Question

please explain why (rad x+4 plus rad 2) becomes x+6+2rad2x+8

Answer 1

Because (a+b)^2 = a^2+ b^2 + 2ab
So... (rad(x+4))^2 + ( rad2)^2+ 2• rad(x+4)•rad(2)= x+4+2+ 2• rad(2•(x+4))= x+8+2 rad( 2x+8)