Question

Hi! i need some help with this question, you don't need to help with the 2 parts, just any 1. Thank you!!

y varies is directly as 3x – 4, and y = 33 when x = 5
Find:
a) y when x = 2
b) x when y = 15​

Answer 1

See explanation

Explanation:

y = k * (3x - 5)

Where,

k = constant of proportionality

y = 33 when x = 5

y = k * (3x - 5)

33 = k * (3 * 5 - 5)

33 = k * (15 - 5)

33 = 15k - 5k

33 = 10k

k = 33/10

k = 3.3

a) y when x = 2

y = k * (3x - 5)

y = 3.3(3 * 2 - 5)

= 3.3(6 - 5)

= 3.3(1)

y = 3.3

b) x when y = 15​

y = k * (3x - 5)

15 = 3.3(3x - 5)

15 = 9.9x - 16.5

15 + 16.5 = 9.9x

31.5 = 9.9x

x = 31.5/9.9

x = 3.18