Which expression is a polynomial?
a. 9x^7y^-3z
b. 4x^3-2x^2+5x-6+1/x
c. -13
d. 13^-2

Option B. is the polynomial.

Step-by-step explanation:

In this question we will simplify every option given

(A)  9x⁷y⁻³z = It is a monomial.

(B) 4x³-2x²+5x-6+1/x  This expression has 5 terms so it's a polynomial.

(C) -13 one term means monomial.

(D) 13⁻² = one term means monomial.

Therefore, Option B. is the polynomial.

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w