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riley reached into his pocket and pulled out a total of 27 coins, consisting of quarters and dimes. if the total value of the coins is $5.55, how many quarters does he have? |
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Answer» Answer: Step-by-step explanation: To solve this, we can set up a system of equations. Let's FIRST name our variables. x: number of quarters y: number of dimes Using this, we can WRITE the following equations. Number of coins: x+y=27 Total Value: 0.25x+0.1y=5.55 We can rewrite the first equation to x=27-y by subtracting y from btoh sides. This way, we can substitute 27-y in for x. 0.25(27-y)+0.1y=5.55 Distribute. 6.75-0.25y+0.1y=5.55 Combine like terms. 6.75-0.15y=5.55 Subtract 6.75 from both sides. -0.15y=-1.2 Divide both sides by -0.15 y=8 There are 8 dimes. We can use that to find the number of quarters by PLUGGING it in to one of the equations. x+y=27 x+8=27 Subtract 8 from both sides. x=19 He has 19 quarters. |
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