Question

$${ \left(x+2 \right) }^{ 2 } = { \left(2x \right) }^{ 2 }$$

Answer

x=-2/3,2

Solution


Use Multiplication Distributive Property: \({(xy)}^{a}={x}^{a}{y}^{a}\).
\[{(x+2)}^{2}={2}^{2}{x}^{2}\]
Simplify  \({2}^{2}\)  to  \(4\).
\[{(x+2)}^{2}=4{x}^{2}\]
Expand.
\[{x}^{2}+4x+4=4{x}^{2}\]
Move all terms to one side.
\[{x}^{2}+4x+4-4{x}^{2}=0\]
Simplify  \({x}^{2}+4x+4-4{x}^{2}\)  to  \(-3{x}^{2}+4x+4\).
\[-3{x}^{2}+4x+4=0\]
Multiply both sides by \(-1\).
\[3{x}^{2}-4x-4=0\]
Split the second term in \(3{x}^{2}-4x-4\) into two terms.
\[3{x}^{2}+2x-6x-4=0\]
Factor out common terms in the first two terms, then in the last two terms.
\[x(3x+2)-2(3x+2)=0\]
Factor out the common term \(3x+2\).
\[(3x+2)(x-2)=0\]
Solve for \(x\).
\[x=-\frac{2}{3},2\]

Decimal Form: -0.666667, 2