a man has dimes and quarters worth 9.50. if he has 50 coins in all, how many dimes and how many quarters does he have ?

Question

tad1 · Answer

10d + 25 q + 9.50
d + q = 50
solve the system

anonymous · Answer

vierd

tad1 · Answer

Solve for d, d= 50 - q
Substitue for d in first equation, etc.

anonymous · Answer

can you show me how to solve the equation? im a little lost

tad1 · Answer

sure
.10d + .25q =9.50 = 10( 50 - q) + 25 q=9.50
5.00 - 10q +25q = 9,50
15q = 9.5-5
15 q = 4.00
q = 4.00/15  I don't think that works.  I'll do it on paper and be right back.

tad1 · Answer

Here we go.
.10d + .25 q = 9.50
make the substitution
.10( 50 - q) + .25q = 9.50
5 - .10q + .35q = 9.50
-,10q +.35 q = 4.50
.25 q = 4.50
q = 17
so d = 50 - 17 =

anonymous · Answer

33 dimes and 17 quarters, thanks !!