Question
Multiply polynomial $ \, \color{blue}{ x+3 } \, $ by $ \, \color{orangered}{ 2x+1 }$.
Answer
$$ \left( \color{blue}{x+3} \right) \cdot \left( \color{orangered}{2x+1} \right) = 2x^2+7x+3 $$
Explanation
In this example we are multiplying two binomials so FOIL method can be used.
$$ \begin{aligned} \left( \color{blue}{ x+3}\right) \cdot \left( \color{orangered}{ 2x+1}\right) &= \underbrace{ \color{blue}{x} \cdot \color{orangered}{2x} }_{\text{FIRST}} + \underbrace{ \color{blue}{x} \cdot \color{orangered}{1} }_{\text{OUTER}} + \underbrace{ \color{blue}{3} \cdot \color{orangered}{2x} }_{\text{INNER}} + \underbrace{ \color{blue}{3} \cdot \color{orangered}{1} }_{\text{LAST}} = \\ &= 2x^2 + x + 6x + 3 = \\ &= 2x^2 + x + 6x + 3 = \\ &= 2x^2+7x+3; \end{aligned} $$This page was created using
Polynomial Operations Calculator