Question 799004
d*10 + q*25 = 515
q=d+8
substitute for q
10d+25(d+8)=515
35d+200=515
{{{ d=(515-200)/35 =315/35 = 9}}}
q=9+8=17

Check:
Value: 0.90 + 17*0.25 = 0.90+4.25 = 5.15