Mr. abernathy purchases a selection of wrenches for his shop. his bill was $78. he buys the same number of $1.50 and $2.50 wrenches, and half that many $4 wrenches. the number of $3 wrenches is one more than the number of $4 wrenches. how many of each did he purchase?

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.