Solve for r
r = \frac{8}{\pi + 4} \approx 1.120198307
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-4r-\pi r=-8
Subtract 8 from both sides. Anything subtracted from zero gives its negation.
\left(-4-\pi \right)r=-8
Combine all terms containing r.
\left(-\pi -4\right)r=-8
The equation is in standard form.
\frac{\left(-\pi -4\right)r}{-\pi -4}=-\frac{8}{-\pi -4}
Divide both sides by -4-\pi .
r=-\frac{8}{-\pi -4}
Dividing by -4-\pi undoes the multiplication by -4-\pi .
r=\frac{8}{\pi +4}
Divide -8 by -4-\pi .
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