Which functions are not linear? Select three such functions. A y=3x2+1y=3x^{2}+1y=3x 2 +1 B y=5−x2y=5-x^{2}y=5−x 2 C y=x5y=\frac{x}{5}y= 5 x D y=−5x−2y=-5x-2y=−5x−2 E −3x+2y=4-3x+2y=4−3x+2y=4 F y=x3y=x^{3}y=x 3