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tigry1 [53]
3 years ago
5

If y varies directly as x and y = 21 when x = 5, find x when y = 42.

Mathematics
1 answer:
Lorico [155]3 years ago
5 0

Answer: 10

<u>Step-by-step explanation:</u>

varies directly means: \frac{y}{x} = k

Step 1: solve for k   ⇒  \frac{21}{5} = k

Step 2: plug in the given value and k to solve for the missing value: \frac{42}{x} = \frac{21}{5}

42(5) = 21(x)

\frac{42(5)}{21} = \frac{21(x)}{21}

2(5) = x

10  = x


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