Answer:
6.397 × 10^9
Step-by-step explanation:
The three inequalities are ...

A graph is useful for this. Satisfying the constraint on calcium will satisfy the other constraints. Correct choices include (1, 5), (4, 1).
So it cuts the y axis at -9 as it has a gradient of 0.
Therefore y=-9 is the equation, as y=mx+c, it intercepts at -9 and has a gradient of 0, therefore y=0x-9 so y=-9.
28 miles in 32 minutes. We need to find how far in 1 minute, so 32 divided by 32 gives us 1 minute. 28 divided by 32 gives 0.875 miles in a minute.
Apply to Beverly. 48 divided by 48 to give 1 minute. 42 divided by 48 is 0.875 miles in a minute.
The answer is yes, they are proportional.