Suppose a certain company sells regular keyboards for $83 and wireless keyboards for $110. last week the store sold three times as many regular keyboards as wireless. if total keyboard sales were $5,385, how many of each type were sold?
regular keyboards :
wireless keyboards:

Step-by-step explanation:

A set of 3 regular and 1 wireless keyboard would sell for ...

  3×$83 +110 = $359

For the given sales, the number of sets sold was ...

  $5385/($359/set) = 15 sets

Since there are 3 regular keyboards in each set, there were 3×15 = 45 regular keyboards sold. The number of each type of keyboards sold is ...

  45 regular keyboards and 15 wireless keyboards

Comment on this solution

When a problem statement tells you the ratio of one kind of item to another, it is often convenient to group the items in that ratio and deal with the groups. Sometimes, there will be a few missing or left over, for example "10 more than 3 times as many." In those cases, you can make an adjustment to the total and still deal with the groups. (Any equations you might write will effectively do this same thing.)

the answer is (4,3)

since the rule for r0, 90º is (-y,x) and it was already applied to form the image, all you have to do is reverse the answer using this formula.