# Graphs - Always make `y` the subject of the formula

The formula for a straight line is `y=mx+c`

If you are given the formula:

`3y-2x=8`

Always make `y` the subject of the formula.

To make `y` the subject of the formula follow this procedure:

`3y-2x=8`

Add `2x` to both sides

`3y-2x+2x=8+2x`

`3y=8+2x`

Divide both sides by 3

`(3y)/3=(2x+8)/3`

Therefore: `y=2/3x+8/3`

**Answer:**

`y=2/3x+2\2/3`

This line can now be plotted on a graph as follows:

First lets calculate some points on the graph.

If

`x=-2` | then `y` | `=2/3(-2)+2\2/3` | `=1.33` |

`x=-1` | then `y` | `=2/3(-1)+2\2/3` | `=2` |

`x=0` | then `y` | `=2/3(0)+2\2/3` | `=2.66` |

`x=1` | then `y` | `=2/3(1)+2\2/3` | `=3.33` |

`x=2` | then `y` | `=2/3(2)+2\2/3` | `=4` |

Now draw the graph and mark out the above points:

Now draw a straight line through these points.

# Graphs - Always make `y` the subject of the formula

The formula for a straight line is `y=mx+c`

If you are given the formula:

`3y-2x=8`

Always make `y` the subject of the formula.

To make `y` the subject of the formula follow this procedure:

`3y-2x=8`

Add `2x` to both sides

`3y-2x+2x=8+2x`

`3y=8+2x`

Divide both sides by 3

`(3y)/3=(2x+8)/3`

Therefore: `y=2/3x+8/3`

**Answer:**

`y=2/3x+2\2/3`

This line can now be plotted on a graph as follows:

First lets calculate some points on the graph.

If

`x=-2` | then `y` | `=2/3(-2)+2\2/3` | `=1.33` |

`x=-1` | then `y` | `=2/3(-1)+2\2/3` | `=2` |

`x=0` | then `y` | `=2/3(0)+2\2/3` | `=2.66` |

`x=1` | then `y` | `=2/3(1)+2\2/3` | `=3.33` |

`x=2` | then `y` | `=2/3(2)+2\2/3` | `=4` |

Now draw the graph and mark out the above points:

Now draw a straight line through these points.