Question

try it tomorrow!
write the equation for the relationship represented in the table. then determine if the relationship represented is additive or multiplicative.

gb storage used, x	cost, y
20	$5
25	$10
40	$25

equation: _______________
additive or multiplicative (circle one)

Explanation:

Step1: Find slope (rate of change)

Calculate $\frac{\Delta y}{\Delta x} = \frac{5-0}{20-15} = \frac{5}{5} = 1$

Step2: Find y-intercept (b)

Use point $(15, 0)$ in $y=mx+b$:
$0 = 1(15) + b \implies b = -15$

Step3: Write linear equation

Substitute $m=1, b=-15$ into $y=mx+b$:
$y = x - 15$

Step4: Classify relationship

Check if change is additive: $\Delta x=5$ for each step, $\Delta y=5$ (constant additive change between y-values relative to x-values; linear relationships are additive).

Answer:

Equation: $y = x - 15$
Additive or Multiplicative: Additive