Question

X = 1, 2, 3 , 4 ,5

y = 15, 12, 9, 6, 3
Write an equation which describes the rule in the following table:

Answer 1

X goes by 1s

And y goes by 3s

Answer 2

• y = -3x + 18

Explanation:

We can see:

• x- values increase by 1 unit
• y- values decrease by 3 units (slope is -3).

This is a linear relationship. Use point-slope form to find the equation:

• y - 15 = -3(x - 1)
• y = -3x + 3 + 15
• y = -3x + 18