In this worksheet, all the answers must be whole positive numbers or zero.
An equation with two variables involves two numbers which must be found.
Look at this equation:
a + b = 8
The two numbers, a and b, must add to 8.
They are whole positive numbers or zero.
What could they be?
If a is 0, b must be 8.
If a is 1, b must be 7.
If a is 2, b must be 6 etc....
The results can be shown in a table:
There are 9 solutions.