Answer:
r=3
Step-by-step explanation:
Divide the numbers
2/r=12/18
2/r=2/3
Multiply all terms by the same value to eliminate fraction denominators
rx2/r=rx2/3
simplify
2=2r/3
multiply all terms by the same value to eliminate fraction denominators again
3x2=3x2r/3
simplify
6=2r
divide both sides if the equation by the same term
6/2=2r/2
r=3
