Tap the blue circles to see an explanation.
$$ \begin{aligned}(x+4)(2x-5)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}2x^2-5x+8x-20 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}2x^2+3x-20\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{x+4}\right) $ by each term in $ \left( 2x-5\right) $. $$ \left( \color{blue}{x+4}\right) \cdot \left( 2x-5\right) = 2x^2-5x+8x-20 $$ |
② | Combine like terms: $$ 2x^2 \color{blue}{-5x} + \color{blue}{8x} -20 = 2x^2+ \color{blue}{3x} -20 $$ |