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Question

Together, one 8-oz serving of plain nonfat yogurt and 1-oz serving of swiss cheese contain 676 mg of calcium. The yogurt contains 4 mg more than twice the calcium in the cheese. Find the calcium content of each food.

Answer 1

So we'll assign variables to the yogurt and cheese:

 

y = yogurt

c = cheese

 

8y + c = 676

 

y = 2c + 4, now you can take this and plug it into the first equation

 

8(2c+4) +c = 676, solve for c

 

16c + 32 + c = 676

 

17c = 644

 

c = 37.88 mg of calcium 

 

Now plug it into the 2nd equation

 

y = 2(37.88)+4 = 79.76 mg of calcium