The number of quarters in sarah's purse is one less than twice the number of dimes she has. if the dimes and quarters total $3.95, how many dimes does she have?

7 dimes

Step-by-step explanation:

Let

x> the number of quarters

y> the number of dimes

Remember that

1 quarter=$0.25

1 dime=$0.10

we know that

0.25x+0.10y=3.95 > Multiply by 100 both sides

25x+10y=395 > equation A

x=2y-1 > equation B

substitute equation B in equation A

25(2y-1)+10y=395

solve for y

50y-25+10y=395

50y+10y=395+25

60y=420

y=7 dimes

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step-by-step explanation: