Answer:
r = 3
Step-by-step explanation:
distribute 3 through the parentheses
1/2r - 3= 12 - 9/2r
multiply both sides of the equation by 2
r - 6 = 24 - 9r
move the variable to the left-hand side and change its sign
r - 6 + 9r = 24
move the constant to the right-hand side and change its sign
r + 9r = 24 + 6
collect like terms
10r = 24 + 6
add the numbers
10r = 30
divide both sides of the equation by 10
r = 3
and you’re done
