Find $ \left(x+5\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}{ 5 }$.

$$ \begin{aligned}\left(x+5\right)^2 = \color{blue}{x^2} +2 \cdot x \cdot 5 + \color{red}{5^2} = x^2+10x+25\end{aligned} $$

Multiply each term of $ \left( \color{blue}{x+28}\right) $ by each term in $ \left( x+14\right) $.

$$ \left( \color{blue}{x+28}\right) \cdot \left( x+14\right) = x^2+14x+28x+392 $$

Combine like terms:

$$ x^2+ \color{blue}{14x} + \color{blue}{28x} +392 = x^2+ \color{blue}{42x} +392 $$

Multiply each term of $ \left( \color{blue}{x^2+42x+392}\right) $ by each term in $ \left( x^2+10x+25\right) $.

$$ \left( \color{blue}{x^2+42x+392}\right) \cdot \left( x^2+10x+25\right) = \\ = x^4+10x^3+25x^2+42x^3+420x^2+1050x+392x^2+3920x+9800 $$

Combine like terms:

$$ x^4+ \color{blue}{10x^3} + \color{red}{25x^2} + \color{blue}{42x^3} + \color{green}{420x^2} + \color{orange}{1050x} + \color{green}{392x^2} + \color{orange}{3920x} +9800 = \\ = x^4+ \color{blue}{52x^3} + \color{green}{837x^2} + \color{orange}{4970x} +9800 $$

Multiply each term of $ \left( \color{blue}{x^4+52x^3+837x^2+4970x+9800}\right) $ by each term in $ \left( x-10\right) $.

$$ \left( \color{blue}{x^4+52x^3+837x^2+4970x+9800}\right) \cdot \left( x-10\right) = \\ = x^5-10x^4+52x^4-520x^3+837x^3-8370x^2+4970x^2-49700x+9800x-98000 $$

Combine like terms:

$$ x^5 \color{blue}{-10x^4} + \color{blue}{52x^4} \color{red}{-520x^3} + \color{red}{837x^3} \color{green}{-8370x^2} + \color{green}{4970x^2} \color{orange}{-49700x} + \color{orange}{9800x} -98000 = \\ = x^5+ \color{blue}{42x^4} + \color{red}{317x^3} \color{green}{-3400x^2} \color{orange}{-39900x} -98000 $$