Multiply polynomial $ \, \color{blue}{ c+4 } \, $ by $ \, \color{orangered}{ c+4 }$.

$$ \left( \color{blue}{c+4} \right) \cdot \left( \color{orangered}{c+4} \right) = c^2+8c+16 $$

In this example we are multiplying two binomials so FOIL method can be used.

$$ \begin{aligned} \left( \color{blue}{ c+4}\right) \cdot \left( \color{orangered}{ c+4}\right) &= \underbrace{ \color{blue}{c} \cdot \color{orangered}{c} }_{\text{FIRST}} + \underbrace{ \color{blue}{c} \cdot \color{orangered}{4} }_{\text{OUTER}} + \underbrace{ \color{blue}{4} \cdot \color{orangered}{c} }_{\text{INNER}} + \underbrace{ \color{blue}{4} \cdot \color{orangered}{4} }_{\text{LAST}} = \\ &= c^2 + 4c + 4c + 16 = \\ &= c^2 + 4c + 4c + 16 = \\ &= c^2+8c+16; \end{aligned} $$

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