Answer:
1. y = 30
2. x = 25
3. z = 250
Step-by-step explanation:
1. y varies directly as x and y = 20 when x = 10. Find y when x = 15
y = kx
20 = k • 10
20/10 = k
2 = k
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y = ?, x = 15
y = 2x
y = 2 • 15
y = 30
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x varies inversely as y when x = 50 when y = 5. Find x when y = 10
xy = k
50 • 5 = k
250 = k
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x = ?, y = 10
xy = 250
x • 10 = 250
x = 250/10
x = 25
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z varies jointly as x and y and z = 30 when x = 2 and y = 3. Find z when x = 5 and y = 10
z = kxy
30 = k • 2 • 3
30 = k • 6
30/6 = k
5 = k
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z = ?, x = 5, y = 10
z = 5xy
z = 5 • 5 • 10
z = 25 • 10
z = 250
