Question on the photo

C

Step-by-step explanation:

Since it is only addition and subtraction, you can rearrange the order of the equations. This is what the three eqautions will look like after the arrangement:

1.6z + 8.3 z = ? (9.9z)

6.2y - 5.1y = ? (1.1y)

4.3x + 5.5x = ? (9.8x)

Then you just add and subtract.

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.