Step by step
The question
Question: F = 25v + 40 is the cost, in dollars, of a gym plan with v visits.
What does 40 mean?
We write the equation big, so we can label it.
1 What the letters mean
F is the cost of a gym plan, in dollars.
v is the number of visits.
2 Make a small table
To see what each number does, we try a few visits: 0, 1 and 2.
0 is where it starts.
v = 0: 25 times 0 is 0.
Plus 40 is 40.
v = 1: 25 times 1 is 25.
Plus 40 is 65.
v = 2: 25 times 2 is 50.
Plus 40 is 90.
Look at the values of F: 40, 65, 90.
Each time v goes up 1, F goes up by 25.
The same number every time.
3 Find the numbers in the table
Now we write the equation again, and label its numbers.
Where does plus 25 each time come from?
From 25v: 25 times v.
Each extra visit adds one more 25.
And 40?
At v = 0, 25 times 0 is 0.
Only 40 is left: the first number in the table.
So 40 is the cost of a gym plan at 0 visits: the start.
Careful!
40 is not multiplied by v.
It is there once, even at 0 visits.
4 Say it in words
So 40 means: the cost of a gym plan is 40 dollars at 0 visits.
That is the start.
5 Check
Let's check with v = 3.
In words: start at 40, then add 25 three times.
We get 115.
The equation with v = 3: 25 times 3 is 75.
Plus 40 gives 115 too.
So the meaning is right!
Let's look back.
First: what the letters mean.
Then: make a small table.
Then: find the numbers in the table.
Then: say it in words.
Last: check.