Answer :
You could do:
1 subtract 9 on both sides of the equation, 1.8r=-5.7r-15
2 then add 5.7r on both sides as well, 7.5r=15
3 divide 7.5 on each side, r=2.
1 subtract 9 on both sides of the equation, 1.8r=-5.7r-15
2 then add 5.7r on both sides as well, 7.5r=15
3 divide 7.5 on each side, r=2.
Add 6 to booth sides.
1.8r+15=5.7r
Subtract 1.8 from both sides
15=3.9r
Divide 15 by 3.9
3.8=r
1.8r+15=5.7r
Subtract 1.8 from both sides
15=3.9r
Divide 15 by 3.9
3.8=r