In this activity, we will be finding the formula that matches the results in the given table.
Example
Find the formula that matches the results in this table.
a | b |
---|---|
2 | 5 |
3 | 7 |
4 | 9 |
10 | 21 |
Which formula will match the results?
1. b = 2a
2. b = 3a - 1
3. b = 2a + 1
Answer
We test out each formula in turn.
b = 2a doesn't work for any of the rows.
b = 3a - 1 works for when a = 2 and b = 5 , but not for the other rows.
b = 2a + 1 works for all the rows, as you have to double the a number and add 1 to get the b number.
So, the answer is b = 2a + 1
Shall we have a go at this now in the following questions?