Write an inequality and use substitution to solve the following problem: chris has 45 dollars saved up. he currently makes 5 dollars each day walking dogs. chris wants to purchase a new stereo for 72 dollars. which of the following numbers of days worked will allow chris to purchase the stereo?

5.4 days (6 days)

Step-by-step explanation:

First set up an equation. (x represents days)

5 dollars a day = 5x ; Already has 45 = +45 ; Needs 72 = =72

That means your equation is...

5x + 45 = 72

Now solve for x.

5x = 27          Subtract 45 from both sides.

x = 5.4          Divide both sides by 5.

This means he will have to work for at least 6 days.

I hope this helped. :)   (I love these kinds of problems!)

-14

step-by-step explanation:

2x2 – 2(x+4)

=2x2-2（5+4）

=4-2×9

=4-18

=-14