Writing y = kx

The question
x4679y24364254y =x

x: 4, 6, 7, 9 y: 24, 36, 42, 54

Write the equation for the table in the form y = kx.

x: 4, 6, 7, 9 y: 24, 36, 42, 54

How it works.

x4679y24364254
24÷4=6
36÷6=6
y=6x
  1. 01

    In a proportional table every y is its x times the SAME number — the constant of proportionality. Find it by dividing a y by its own x.

  2. 02

    Take the first column: 24 ÷ 4 = 6.

  3. 03

    Check another column so it is not a fluke: 36 ÷ 6 = 6. Every column gives 6, so the constant is 6.

  4. 04

    So the equation is y = 6x — it says "each y is x times 6".