# The variables A, B, and C represent polynomials where A=x+ 1, B=x^2+2x-1, and c=2x. What is AB+C in simplest form?

${x}^{3} + 3 {x}^{2} + 3 x - 1$
$A B + C = \left(x + 1\right) \left({x}^{2} + 2 x - 1\right) + \left(2 x\right)$
$= {x}^{3} + 2 {x}^{2} - x + {x}^{2} + 2 x - 1 + 2 x$
$= {x}^{3} + 3 {x}^{2} + 3 x - 1$