lena purchased a prepaid phone card for $20. long distance call cost 18 cents a minute using this card. Lena used her cared only once to make a libg distance call. if the remaining credit on her card is $13.34, how many minutes did her call last?

37 minutes

Step-by-step explanation:

We start by finding the difference between the original amount and what is left

Mathematically, that will be;

20-13.34 = 6.66

To

cents that will be 6.66 * 100 = 666 cents

We now divide by the amount per minute

The amount per minute is 18 cents

Thus, the number of minutes will

be 666/18 = 37

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15