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Dafna1 [17]
4 years ago
8

Sarah went to an electronics store, purchased 3 CDs and 5 DVDs, and spent $137. Michelle went to the same store, bought 2 CDs an

d 7 DVDs, and spent $161. How much does each CD sell for at the store? . . a) $13 . . b)$14 . . c)$18 . . d) $19 . .
Mathematics
2 answers:
dangina [55]4 years ago
8 0

Answer:

b) $14

Step-by-step explanation:

Let x be the cost of each CD and y be the cost of each DVD,

Since, 3 CDs and 5 DVDs cost $ 137,

⇒ 3x + 5y = 137 -------(1),

Also, 2 CDS and 7 DVDs cost $ 161,

⇒ 2x + 7y = 161 --------(2),

7 × equation (1) - 5 × equation (2)   ( ∵ we need the value of x so we have to eliminate y for this LCM(7,5) = 35 )

We get,

21x - 10x = 959 - 805

11x = 154

⇒ x = \frac{154}{11} = 14

Hence, the cost of each CD is $ 14,

Option 'b' is correct.

vesna_86 [32]4 years ago
5 0
C. thats the only one that will give you the same price for the DVDS as well. they charge $14 for CDS and $19 for DVDS
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<h3>What is the equation of a circle?</h3>

Let, the equation of a circle exists:

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We rewrite the equation and set them equal :

$(x-h)^2 + (y-k)^2 - r^2 = x^2+y^2- 32x - 60y +1122=0

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We solve for each coefficient meaning if the term on the LHS contains an x then its coefficient exists exactly as the one on the RHS containing the x or y.

-2hx = -32x

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3 years ago
Two counters are selected at random from a bag containing 5 red counters and 3 blue counters.
azamat

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