a Define a variable and create expressions for what you pay and what your friend pays. When you pay the same, these expressions will be equal.
B
b Substitute x=12 into the expressions you have found.
A
a At 11 months
B
b Yes, see solution.
Practice makes perfect
a We subscribe to cable TV while our friend chose satellite TV. We want to see if their expenses for a year are less than ours. First, we will define a variable. Let x be the number of months for which cable TV is purchased.
x Since we pay 45 dollars per month, we can write the expression representing the entire cost.
45x
The price our friend paid consists of two parts.
A flat fee of 99 dollars for a satellite dish
A flat rate of 36 dollars per month.
Now we can write the following expression representing how much our friend paid.
36x+ 99
We will now set the expressions equal to each other. Solving the equation will tell us when we have paid the same amount as our friend.
