Question

1.

Answer 1

Answer:

A

Step-by-step explanation:

Let d be the total number of computer desks and c be the total number eof single drawer file cabinets.

1. A computer desk weighs 50 pounds, then d computer desks weigh 50d pounds. A single drawer file cabinet weighs 30 pounds, then c cabinets weigh 30c pounds. In total, a train car can hold 1500 pounds of cargo, so

50d+30c=1500

2.  A computer desk occupies a space of 4 cubic feet, then d computer desks occupy 4d cubic feet. A single drawer file cabinet occupies a space of 3 cubic feet, then c cabinets occupy 3c cubic feet. In total, a train car can hold 138 cubic feet of space, so

4d+3c=138.

Thus, we get a system of two equations:

$\left \{ {{50d+30c=1500} \atop {4d+3c=138}} \right.$