Is this considered algebra? "what was the cost of each pair of socks?"

GRADUATE

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Nov 23, 2015
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I am stuck unfortunately.

The equation: Dominic bought a pair of shoes for $90, two t-shirts for $20 each, and four pairs of socks. If he paid 8% sales tax on the entire purchase, and if the total amount of the tax he paid was $12, what was the cost of each pair of socks?

Where I am at thus far:

8/100 (90+2×20+4x) =12
8/100 (130+4x)=12

The answer is supposed to be 5, but I don't know how to get to that.
 

stapel

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Dominic bought a pair of shoes for $90, two t-shirts for $20 each, and four pairs of socks. If he paid 8% sales tax on the entire purchase, and if the total amount of the tax he paid was $12, what was the cost of each pair of socks?
How much, in actual money, was spent for taxes? (Hint: Copy.)

How much, as a percentage, was spent for taxes? (Hint: Copy.)

If taxes in (that dollar amount) was (that percentage) of (the total), what equation does this create? (Hint: [dollars in taxes] are equal to [percentage] of [dollars for purchase].) (here)

What value do you get for the total dollars in purchases? (Hint: Solve the linear equation.) (here)

Where I am at thus far:

8/100 (90+2×20+4x) =12
8/100 (130+4x)=12
What did you get when you multiplied through by 100 to get rid of the fraction? What did you get when you divide through by 8 to release the parenthetical? What did you get when you subtracted off the 130 to the right-hand side? What did you get when you divided through to solve the equation?

Please be complete. Thank you! ;)
 

Mrspi

Senior Member
Joined
Dec 17, 2005
Messages
2,128
I am stuck unfortunately.

The equation: Dominic bought a pair of shoes for $90, two t-shirts for $20 each, and four pairs of socks. If he paid 8% sales tax on the entire purchase, and if the total amount of the tax he paid was $12, what was the cost of each pair of socks?

Where I am at thus far:

8/100 (90+2×20+4x) =12
8/100 (130+4x)=12

The answer is supposed to be 5, but I don't know how to get to that.
You could write 8% as 0.08 (which is the same thing as 8/100, of course, but might look less "scary.")

0.08(130 + 4x) = 12

You could use the distributive property to get rid of the parentheses:

0.08*130 + 0.08*4x = 12
10.40 + 0.32x = 12

Can you finish it now?
 
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