Y varies directly with x, y=65 when x=5. How do you find y when x=12?

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Answer 1 · 2018-04-07T02:22:53

$156$

$y$ varies directly with $x$

$y ∝ x$

$y = kx color(white)(...)["where"\ k = "proportionality constant"]$

When $y = 65, x = 5$

$65 = k × 5$

$k = 65/5 = color(blue)(13)$

When $x = 12$

$y = kx = color(blue)(13) × 12 = 156$