**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

*, must add to 8.*

**b**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:

a | b |
---|---|

0 | 8 |

1 | 7 |

2 | 6 |

3 | 5 |

4 | 4 |

5 | 3 |

6 | 2 |

7 | 1 |

8 | 0 |

There are **9 solutions**.