Answer:
y = 18
Step-by-step explanation:
Direct variation means y will change by the same factor x does. When x changes by a factor of 15/10 = 1.5, the value of y will change by that same factor
x = 10, y = 12
x= 15, y = 1.5×12 = 18
The new value of y is y = 18.
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Written as a proportion, you have ...
y/15 = 12/10
y = 15×12/10 = 18
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Written as a direct variation equation, you have ...
y = kx
12 = k·10 ⇒ k = 1.2
y = 1.2·15 = 18 . . . . for x=15
