what is 1.8r+9=-5.7r-6
You could do:1 subtract 9 on both sides of the equation, 1.8r=-5.7r-152 then add 5.7r on both sides as well, 7.5r=153 divide 7.5 on each side, r=2.
Add 6 to booth sides.1.8r+15=5.7rSubtract 1.8 from both sides15=3.9rDivide 15 by 3.93.8=r