Question

If y varies directly ás x, and y = 7 when x = 3. find y when x=7

Answer 1

Answer:

y = $\frac{49}{3}$

Step-by-step explanation:

Given y varies directly as x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition

x = 3 when y = 7

k = $\frac{y}{x}$ = $\frac{7}{3}$, thus

y = $\frac{7}{3}$ x ← equation of variation

When x = 7, then

y = $\frac{7}{3}$ × 7 = $\frac{49}{3}$