Answer:
0.25q + d ≥ 18
q ≥ 20
Step-by-step explanation:
A piggy bank contains quarters and dollar bills.
Let there be q quarters and d dollars.
There is at least $18 in the piggy bank.
i.e. 0.25q + d ≥ 18
piggy bank has at least 20 quarters.
i.e. q ≥ 20
Hence, systems which correctly describe the possible number of quarters (q) and dollar bills (d) in the piggy bank is:
0.25q + d ≥ 18
q ≥ 20