Question

If y varies directly as x, and y is 180 when x is n and y is n when x is 5, what is the value of n?

Answer 1

Answer:

n = 30

Step-by-step explanation:

Given that 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 y = 180 when x = n, then

180 = kn ( divide both sides by n )

k = $\frac{180}{n}$

y = $\frac{180}{n}$ x ← equation of variation

y = n when x = 5, thus

n = $\frac{180}{n}$ × 5 = $\frac{900}{n}$ ( multiply both sides by n )

n² = 900 ( take the square root of both sides )

n = $\sqrt{900}$ = 30