Question

Given the equation y=5-0.4x, identify if it represents growth or decay, if it is linear or exponential, and what the initial amount is.

Answer 1

Decay, linear, 5.

Explanation:

To rewrite the equation in y = mx + b form, y = -0.4x + 5.

The slope (m) is negative (-0.4x), so the line is decreasing to the right, or decaying.

It is linear because there is no exponents in the equation, or the exponent on x is 1.

The initial amount is another word for the y-intercept, what the value is at x=0, which is 5, or (0, 5) depending on how your teacher wants you to represent it.