Answer:
3r + 5
Step-by-step explanation:
by "combining like terms", this means that if we have, for example,
1 * x + 5 * x, we can factor this out to be x*(1+5) = 6 * x and the like terms (1x and 5x) are combined
thus, we have
-5r + 8r + 5
the "like terms" here are -5r and 8r because they both have an r attached to it. thus, we can set out to only factor the r in these two numbers, resulting in
-5 * r + 8 * r + 5 = r * (-5 + 8) + 5 = r * 3 + 5 = 3r + 5
