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.

*"I think of two numbers.*

*When I double the first and add this to the second, I get 8."*

Written using algebra, where * a *and

*stand for my two numbers, we get:*

**b**

**2a + b = 8**

This means that* twice a* added to

*must come to 8.*

**b*** a and b* 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 8 - 2 = 6*.

If * a is 2, b must be 8 - 4 = 4*.

If* a is 3, b must be 8 - 6 = 2*.

If* a is 4, b must be 8 - 8 = 0*.

The results can be shown in a table:

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

0 | 8 |

1 | 6 |

2 | 4 |

3 | 2 |

4 | 0 |

There are **5 solutions.**