Roast beef has 25g of protein and 11g of calcium per serving. A serving of mashed potatoes has 2g of calcium and 25g of calcium. How many servings of each are needed to supply exactly 25g of protein and 61g of calcium?

Relax

Respuesta :

Let R and M be the numbers of serving of roast beef and mashed potato.

25R     +    2M      =   29   =====>  1

11R      +     25M      =     61 =====>    2

From (1): 2R   =   29    -    25M

or     M   =     29/2     - 25/2 R

Substitute this into (2):

11R      +      25(29/2     -     25/2 M)     =     61

11R      +       362.5      -       312.5R     =     61

301.5      =       301.5R

R      =        1

Using    R     =     1, we can get

11(1)      +     25M     =      61

25M       =      50

M         =           2

Therefore, you will need ONE SERVING  of Roast Beef and TWO SERVINGS of Mash Potatoes.




Hope that helps!!!!                                                : )