Answer:
![x = (-r - 21)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/gceytssce607lihkz0szroda8am2bedmiz.png)
Explanation:
Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Remember to do the opposite of PEMDAS.
PEMDAS =
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
First, subtract 6 from both sides:
2x + 6 (-6) = -r - 15 (-6)
2x = -r + (-15 - 6)
2x = -r + (-21)
2x = - r - 21
Next, divide 2 from both sides:
![(2x)/(2) = (-r - 21)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/kap30nwvlqjo1t0wdtd5nkjufrh0m5efzm.png)
![x = (-r - 21)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/gceytssce607lihkz0szroda8am2bedmiz.png)
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