Solving this kind of problem is easier if you take steps to make the coefficient of the unknown a positive one. Adding 0.6r to both sides makes the coeff. of r a positive one: 0.6r greater than or equal to 2.9+1.3.
0.6r then is equal to or greater than 4.2. Divide both sides by 0.6 to isolate r:
r greater than or equal to 7.
Let r be represented by the horizontal number line. Darken r = 7 and also darken the r axis to the right of r=7.
