How do you graph y<-5x+4?

May 17, 2016

See the explanation

Explanation:

Just for a moment look upon this inequality as though it is an equation. In which case you would write $y = - 5 x + 4$

This is the line that you need to draw.

However, this is an inequality which effects the format of the line . As y is less than $- 5 x + 4$ it means that y can never be equal to $- 5 x + 4$. Suppose you chose $x$ to be 3 then we have $- 5 \left(3\right) + 4 \to - 11$ so y will assume $\underline{\text{all}}$ the values less than -11 in this instance. This is true for any $x$ value you chose.

As the scenario is 'less than' it is depicted in the graph by a dotted line. If we had $y \le$ then we would use a solid line.
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Obtaining the line

Substitute 2 values for $x$ into the inequality to find the paired values of $y$. Mark these points on the graph paper and draw a 'dotted' line through them extending to the edge of the squared area of the paper. Title the graph and mark the two points used. If you wish to be really flash, include a table that shows the calculation of the two points (3 points is better)