A diabetes prescription costs $78 online. This is 75% of the cost of the in-store prescription. How much is the in-store prescription? ( with a explanation and work)

$104

Step-by-step explanation:

1. Set up your problem as a ratio. Put the percentage over 100 on one side of the equation and the the cost of the online prescription over the in-store prescription on the other side. Since we don't know the cost of the in-store prescription, we can write this as x.

78/x = 75/100

2. Next, cross multiply.

75x = 7800

3. Divide by 75 on both sides.

x = 104

4. To check your work, multiply 104 by .75 (the decimal equivalent of 75%) to make sure you get back to the original $78.

104 x .75 = 78

Now you know that your answer is correct.

Hope this helps!

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step-by-step explanation:

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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