Answer:
r = -12
Step-by-step explanation:
[tex]3+\dfrac{r}{-4}=6\\\\\dfrac{r}{-4}=3 \qquad\text{subtract 3}\\\\r=-12 \qquad\text{multiply by -4}[/tex]
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If the numerator is (3+r), parentheses are needed. In that case, r=-27.
[tex]\dfrac{3+r}{-4}=6\qquad\text{multiply both sides by (-4)}\\\\(-4\!\!\!\!\diagup^1)\cdot\dfrac{3+r}{-4\!\!\!\!\diagup_1}=(-4)(6)\\\\3+r=-24\qquad\text{subtract 3 from both sides}\\\\3-3+r=-24-3\\\\r=-27[/tex]
