Answer:
d = 100
Step-by-step explanation:
0.1d + 0.25(10) = 12.5
0.1d + 2.5 = 12.5
0.1d + 2.5 - 2.5 = 12.5 - 2.5
0.1d = 10
0.1d × 10 = 10 × 10
