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

$$ \begin{aligned} \left( \color{blue}{ 32x-81}\right) \cdot \left( \color{orangered}{ 2x+5}\right) &= \underbrace{ \color{blue}{32x} \cdot \color{orangered}{2x} }_{\text{FIRST}} + \underbrace{ \color{blue}{32x} \cdot \color{orangered}{5} }_{\text{OUTER}} + \underbrace{ \left( \color{blue}{-81} \right) \cdot \color{orangered}{2x} }_{\text{INNER}} + \underbrace{ \left( \color{blue}{-81} \right) \cdot \color{orangered}{5} }_{\text{LAST}} = \\ &= 64x^2 + 160x + \left( -162x\right) + \left( -405\right) = \\ &= 64x^2 + 160x + \left( -162x\right) + \left( -405\right) = \\ &= 64x^2-2x-405; \end{aligned} $$

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