You have $7.25 in pennies and dimes. The number of dimes is 4 less than five times the number of pennies.

Question

anonymous · Answer

d=5p-4, i think is the equation to get the number dimes. So then you would take the number of dimes and add pennies to it until you get $7.25.

anonymous · Answer

can you explain more in to detail? I'm still not understanding it.

anonymous · Answer

Wait, I think I did it wrong. Idk, sorry

pfenn1 · Answer

Say p=number of pennies and d=number of dimes.  You know that the number of dimes and pennies add up to $7.25.  Pennies are worth $0.01 and dimes are worth $0.10.  So we know that$$0.01p+0.10d=7.25$$Do you understand that part?

anonymous · Answer

yes i understand that part

pfenn1 · Answer

The trick with "word" problems is that you have to learn to translate the "words" into mathematical equations. For instance,

The number of dimes is 4 less than five times the number of pennies.
                        d        = -4                5      x                          p

pfenn1 · Answer

So this is exactly how @crazycookiecat came up the equation above. So now you have two equation and two unknowns. $$0.01p+0.10d=7.25$$$$d=5p-4$$Substitute and solve.

anonymous · Answer

Thank you :)

pfenn1 · Answer

You're welcome