SOLUTION: I need some help with Linear Systems as word problems. I know how to do the work, I just need help setting up the equation for the problem.

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Question 519603: I need some help with Linear Systems as word problems. I know how to do the work, I just need help setting up the equation for the problem.
- Rod has 40 coins, all dimes and quarters, worth $7.60. How many dimes and how many quarters does he have?
I use 'd' for dimes and 'q' for quarters.
For my first equation I got d+q=40. I don't know what the second equation is though.
Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
You are right!
You need a second equation in which you equate the total value of the coins to the total sum given i.e. $7.60
Note that each quarter is worth $0.25 and each dime is worth $0.10, so...

So now you have a system of two equations in two unknowns (q and d).
Rewrite the first equation d+q = 40 as d = 40-q and substitute into the second equation to get:
Simplify and solve for q.

Subtract 4.
Divide by 0.15
and

SOLUTION: I need some help with Linear Systems as word problems. I know how to do the work, I just need help setting up the equation for the problem. - Rod has 40 coins, all dimes and qua