The price of an item has dropped to $68 today. Yesterday it was $80. Find the percentage decrease.

15 percent

Step-by-step explanation:

15%

Step-by-step explanation:

(80-68)*(100/80)=15%

The two equations are:

y = 5*x + 3

y = 5.5*x + 2

Step-by-step explanation:

By definition:

speed = distance/time

it can be rewritten as:

time = distance/speed

During the first half of the race Ben ran at a rate of 5 miles per hour for x hours and walked 3 miles. Let's call y, the number of miles in half the race; then he ran y-3 miles. The time he spend was:

x = (y-3)/5

Analogously, for the second half:

x = (y-2)/5.5

These two equations can be rewritten as

y = 5*x + 3

y = 5.5*x + 2

Which means that:

5*x + 3 = 5.5*x + 2

3-2 = 5.5*x -5*x

1 = 0.5*x

x = 2 hours

When you are solving for the variables in a situation represented by two equations you can isolate the same variable in both equations and equate the two terms, getting a new equation with only one variable. Another option is to isolate one variable in one equation and replace it in the other one.