Question

I need help with problem

Answer 1

D + q = 40
.10d +.25q= $7.75

d +q = 40
d =40-q
.10(40-q) +.25q= $7.75
4 - .10q + .25q =7.75
4 +.15q =7.75
4-4 +.15q =7.75-4
.15q= 3.75
.15q/.15 = 3.75/.15
q = 25

d =40-25
d = 15

Check
.10(15) +.25(25)= $7.75
1.5+6.25=7.75
7.75=7.75