Select which equations are polynomials and which are not polynomials. a) -x^5+7x-1/2x^2+9 b) x^3-4x-3 c) 4 / x^2-4x+3 d)x^4+5/x^3-√x+8 e) |x|^2+4√x-2 f) x^4+x^3√7+2x^2-√3/2x+π

In Polynomials all the exponents of x-variable must be positive integers, then polynomials are:
a) -x^5+7x-1/2x^2+9, the exponents of x's are: 5, 1, and 2
b) x^3-4x-3, the exponents of x's are: 3, and 1
f) x^4+x^3√7+2x^2-√3/2x+π, the exponents of x's are: 4, 3, 2, and 1

Not polynomials are:
c) 4 / x^2-4x+3 = 4x^(-2)-4x+3, the exponents of x's are -2, and 1
d) x^4+5/x^3-√x+8=x^4+5x^(-3)-x^(1/2)+8, the exponents of x's are 4, -3, and 1/2
e) |x|^2+4√x-2=|x|^2+4x^(1/2)-2, the exponents of x's are 2 and 1/2