Please help me, I do not understand.

9514 1404 393

  p : q = 3 : 2

Step-by-step explanation:

You are given sufficient information to write two relations involving p and q. We presume these will be sufficient to find an answer to the question. We will be able to find p and q. Then we can find their ratio, as the problem asks.

  (p-15)/(q-15) = 2/1

  (p+30)/(q+30) = 5/4

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From the first equation, we get ...

  p -15 = 2(q -15)

  p = 2q -15 . . . . . . . add 15, simplify

From the second equation, we get ...

  4(p +30) = 5(q +30)

  4p + 120 = 5q + 150

  4p = 5q + 30

Using the first equation to substitute for p, we have ...

  4(2q -15) = 5q +30

  8q -60 = 5q +30 . . .  eliminate parentheses

  3q = 90 . . . . . . . . . . . add 60-5q to both sides

  q = 30 . . . . . . . . . . . . divide by 3

  p = 2q -15 = 2(30) -15 = 45

Then the desired ratio is ...

  p : q = 45 : 30

  p : q = 3 : 2

the answer is 15% decrease