Question

M varies directly as n, and m=14 when n=7

a) write an equation that relates m and n

b) find m when n = 16

c) find n when m = 30

Answer 1

see explanation

Explanation:

(a)

given m varies directly as n then the equation relating them is

m = kn ← k is the constant of variation

to find k use the condition m = 14 when n = 7

14 = 7k ( divide both sides by 7 )

2 = k

m = 2n ← equation of variation

(b)

when n = 16 , then

m = 2 × 16 = 32

(c)

when m = 30 , then

30 = 2n ( divide both sides by 2 )

15 = n