Question
Answer
$$x\cdot(4-x)+(-2)^2=-x^2+4x+4$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}x\cdot(4-x)+(-2)^2& \xlongequal{ }x\cdot(4-x)+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}4x-x^2+4 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-x^2+4x+4\end{aligned} $$ | |
| ① | Multiply $ \color{blue}{x} $ by $ \left( 4-x\right) $ $$ \color{blue}{x} \cdot \left( 4-x\right) = 4x-x^2 $$ |
| ② | Combine like terms: $$ -x^2+4x+4 = -x^2+4x+4 $$ |
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Simplify Rational Expressions