Solve each question. Round to the nearest tenth if necessary.
7r – 7 = 2r + 18
A. r = –5
B. r = 5
C. r = 2.2
D. r = 1.2
5! thanks Ms. Sue!
To solve the equation 7r - 7 = 2r + 18, we need to isolate the variable r on one side of the equation. Here's how you do it step by step:
1. Start by combining the terms involving r on one side of the equation:
Subtract 2r from both sides:
7r - 2r - 7 = 2r - 2r + 18
Simplify:
5r - 7 = 18
2. Next, isolate the r-term by moving the constant term to the other side of the equation.
Add 7 to both sides:
5r - 7 + 7 = 18 + 7
Simplify:
5r = 25
3. To solve for r, divide both sides of the equation by 5:
(5r)/5 = 25/5
Simplify:
r = 5
Therefore, the answer is B. r = 5.
7r – 7 = 2r + 18
Subtract 2r from both sides
Add 7 to both sides
5r = 25
r = ?