Giuliana has 22 quarters and dollar coins worth a total of $10.75.

Which equation can be used to find d, the number of dollar coins Giuliana has?

Given:

22 quarters and dollar coins worth 10.75

quarters = 0.25

dollar = 1.00

q + d = 22

0.25q + d = 10.75

q = 22 - d

0.25 (22-d) + d = 10.75

5.5 - 0.25d + d = 10.75

0.75d = 10.75 - 5.5

0.75d = 5.25

d = 5.25/0.75

d = 7