If y=kx, where k is a constant, and y=24 when x=6, what is the value of y when x=5?

Answer choices:
A) #-6x-5#
B) #6x+5#
C) #6x-5#
D) #6x^2-15x#

I keep getting #y=20#, but it's none of these choices

1 Answer
Jul 26, 2018

You're right

Explanation:

Solving for k,
y = kx
24 = k(6)
k = 4

Substitute in k and given x,
y = 4x = 4(5) = 20

Option A: #-6(5) - 5 = -35#
Option B: #6(5) + 5 = 35#
Option C: #6(5) - 5 = 25#
Option D: #6(5)^2 - 15(5) = 75#

None of the options is equal to 20 when x = 5.