For question number 1 pls help, and show work step by step

The answer for this problem would be [tex]\left[\begin{array}{ccc}r=7\end{array}\right] \\[/tex].
We are going to solve your equation step-by-step.
Step 1: Subtract r from both sides.
7r−15−r=r+27−r
6r−15=27
Step 2: Add 15 to both sides.
6r−15+15=27+15
6r=42
Step 3: Divide both sides by 6.
6r/6=42/6
The answer for this is r=7.