Dave bought 4 cookies at a bake sale if each cookie cost 0.85 and he paid with a twenty dollar bill how much change should he get back

$16.6 dollars back

Step-by-step explanation:

The answer is $16.6 because 0.85 times 4 is 3.4 and 20 minus 3.4 is 16.6

the graph in the attached figure

step-by-step explanation:

we have

using a graphing tool

the graph in the attached figure

the roots are ( x-intercepts) x=-0.5,x=1,x=3

the y-intercept is the point (0,3)