We are asked to express r in terms of A, P, and t.
We first divide both sides of the equation by t, which gives us

,
then, dividing both sides by P, we have

.
Swap the sides:
Finally subtracting 1 from both sides gives us

.
The second plant would because it grew one more inch in one less month (that's faster) than the other plant.
Answer:
The variable in that expression is x
Answer:
B) 6(x+2y) + 4 = 6x + 12 y + 4