Plotting lines on graph paper

Example 1

Plot the graph of ` y = x`

This actually means `y=mx+c`

`y=1x+zero`

Graph of `y=x`

First lets calculate some points on the graph.

`x=-2` then `y=-2`

`x=-1` then `y=-1`

`x=0` then `y=0`

`x=1` then `y=1`

`x=2` then `y=2`

Now draw a graph and mark on the above points

Mark the points on a graph

Now draw a straight line through these points

Connect the positions up y=x

Example 2

Plot the graph of `y+x=5`

Always put the formula in the form `y=mx+c`

`y=-1x+5`

First lets calculate some points on the graph.

`x=-2` then `y=-1(-2)+5=7`

`x=-1` then `y=-1(-1)+5=6`

`x=0` then `y=-1(0)+5=5`

`x=1` then `y=-1(1)+5=4`

`x=2` then `y=-1(2)+5=3`

Now draw a graph and mark on the above points

Mark the points on a graph

Now draw a straight line through these points

Find the gradient of the resulting line

Example 3

Plot the graph of `2y -3x=7`

Always put the formula in the form `y=mx+c`

`2y=3x+7`

`y=3/2x+7/2`

`y=1\1/2x+3\1/2`

First lets calculate some points on the graph.

`x=-2` then `y=1.5(-2)+3.5=0.5`

`x=-1` then `y=1.5(-1)+3.5=2`

`x=0` then `y=1.5(0)+3.5=3.5`

`x=1` then `y=1.5(1)+3.5=5`

`x=2` then `y=1.5(2)+3.5=6.5`

Now draw a graph and mark on the above points

Mark the points on a graph

Now draw a straight line through these points

Find the gradient of the line but be careful, they are not all whole numbers