So as you can see there are two clear rates at which the plant is growing or will grow in the future, wehave Plant A that grows at 3 cm a month so we multiply that by the number of months, and the plant B and we just have to add to the current height thefuture height whihc will be calculater by multiplying the rate by the number of months:
(-$11) x 12. That would be the equation because there are 12 months, so you would multiply -11 from 12 to get -132 every year for the tennis club membership.
