Number of cubes increases by 3 for each term.
an= 3n+1
Y = mx + b
b: y-intercept (when x equals zero)
m: slope ((y₂ - y₁) ÷ (x₂ - x₁))
Y - Intercept:
To find the y-intercept, just look at the table. The y-intercept is whatever y equals when x equals zero. In this case it is -8.
Slope:
(y₂ - y₁) ÷ (x₂ - x₁)
Pick two points and substitute them into this equation. Let's use (-3, 1) and (-2, -2).
(-2 - 1) ÷ (-2 + 3)
-3 ÷ 1
-3
Now substitute these values back into the equation.
y = mx + b
y = -3x - 8
The answer is a.
