Find $ \left(x+10\right)^2 $ using formula.

$$ (A + B)^2 = \color{blue}{A^2} + 2 \cdot A \cdot B + \color{red}{B^2} $$

where $ A = \color{blue}{ x } $ and $ B = \color{red}{ 10 }$.

$$ \begin{aligned}\left(x+10\right)^2 = \color{blue}{x^2} +2 \cdot x \cdot 10 + \color{red}{10^2} = x^2+20x+100\end{aligned} $$

Multiply each term of $ \left( \color{blue}{x+18}\right) $ by each term in $ \left( x^2+20x+100\right) $.

$$ \left( \color{blue}{x+18}\right) \cdot \left( x^2+20x+100\right) = x^3+20x^2+100x+18x^2+360x+1800 $$

Combine like terms:

$$ x^3+ \color{blue}{20x^2} + \color{red}{100x} + \color{blue}{18x^2} + \color{red}{360x} +1800 = x^3+ \color{blue}{38x^2} + \color{red}{460x} +1800 $$

Multiply each term of $ \left( \color{blue}{x^3+38x^2+460x+1800}\right) $ by each term in $ \left( x+1\right) $.

$$ \left( \color{blue}{x^3+38x^2+460x+1800}\right) \cdot \left( x+1\right) = x^4+x^3+38x^3+38x^2+460x^2+460x+1800x+1800 $$

Combine like terms:

$$ x^4+ \color{blue}{x^3} + \color{blue}{38x^3} + \color{red}{38x^2} + \color{red}{460x^2} + \color{green}{460x} + \color{green}{1800x} +1800 = \\ = x^4+ \color{blue}{39x^3} + \color{red}{498x^2} + \color{green}{2260x} +1800 $$

Multiply each term of $ \left( \color{blue}{x^4+39x^3+498x^2+2260x+1800}\right) $ by each term in $ \left( x-2\right) $.

$$ \left( \color{blue}{x^4+39x^3+498x^2+2260x+1800}\right) \cdot \left( x-2\right) = \\ = x^5-2x^4+39x^4-78x^3+498x^3-996x^2+2260x^2-4520x+1800x-3600 $$

Combine like terms:

$$ x^5 \color{blue}{-2x^4} + \color{blue}{39x^4} \color{red}{-78x^3} + \color{red}{498x^3} \color{green}{-996x^2} + \color{green}{2260x^2} \color{orange}{-4520x} + \color{orange}{1800x} -3600 = \\ = x^5+ \color{blue}{37x^4} + \color{red}{420x^3} + \color{green}{1264x^2} \color{orange}{-2720x} -3600 $$