Item 19 you pay $40 each month for satellite tv, plus $3.50 for every movie you purchase. write and solve an equation to find the number of movies purchased during a month with a total bill of $57.50.

Let x be the number of movies purchased. If each movie you purchase costs $3.50 dollars, this means that the total cost of x movies in one month is $3.50x
In addition, you have to pay $40 for satellite TV. We can now find an equation to find the total cost per month:
40 + 3.50x

Now, by hypothesis, you paid $57.50 during a month as a total bill.
Which means that 40 + 3.50x = 57.50
We need to find the number of movies purchased during that month, or, in mathematical words, we need to solve for x.

40 + 3.50x = 57.50

First, let's put the variables apart and the numbers apart by subtraction 40 from each side, so we get:
40 - 40 + 3.50x = 57.50 - 40
3.50x = 17.50

Now divide both sides by 3.50
(3.50x)/(3.50) = 17.50 / 3.50
x = 5

So, during that month, you purchased 5 movies.

Hope this helps! :)