Author Topic: 8th grade pre-algebra problem  (Read 536 times)

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Offline Malachai the Dove

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8th grade pre-algebra problem
« on: October 29, 2013, 08:50:47 pm »
Okay, I was flying through this worksheet until question four reared it's ugly head. Here it is, "Estimate the number of T-shirts for which the total cost from both companies is equal."
Company A's algebraic expression: 8x+15=y
Company B's algebraic expression: 5.50x+49.95=y
Key: X=Shirts
Y=Price
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If anyone can, please help.

Offline MessedThoughts

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Re: 8th grade pre-algebra problem
« Reply #1 on: October 29, 2013, 10:47:03 pm »
Im tired so if i read the question wrong or i did something that doesn't make sense, its cause its late

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Based on the two expressions

8x + 15 = 5.5x + 49.45
8x-5.5x = 49.95 - 15
2.5x = 34.45
x = 13.98

now substitute x into both equations to check the Y values are both equal

8(13.98) + 15 = 126.84
5.5(13.98) + 49.95 = 126.84

Since we are looking for a whole number of tshirts, round 13.98 to 14

Therefore the  number of T-shirts for which the total cost between company A and B is closest to equal is 14 T-shirts
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