Respuesta :
Answer:
r=(
Step-by-step explanation:
- Solving: 21+3r=48
Solving for variable 'r'
Move all terms containing r yo the left, all other terms to the right.
Add '21' to each side of the equation
21+ -21+3r= 48+ -21
Combine like terms:
21+ -21=0
0+3r =48 + -21
3r= 48+ -21
Combine like terms: 48+ -21 =27
3r=27
Divide each side by '3'.
r=9
Simplifying:
r=9