The median household income in the US grew linearly from approximately $30, 000 in 1990 to $48, 000 in 2006. Let x be the number of years since 1990. Express the median income as a function of x. Use this function to approximate the median income in 2030. What is the significance of the slope of this function

--- The equation

The median income in 2030 is $75000

Step-by-step explanation:

Given

Represent years since 1990 with x and the income with y.

So, we have:

--- In 1990

--- In 2006

Solving (a): Express as a function.

First, we calculate the slope

The equation is then calculated as:

This gives:

Open bracket

Solving (b): Income in 2030.

In 2030, x = 40.

Substitute 40 for x in

Solving (c): The significance of the slope.

In (a), the slope is calculated as 1125.

This implies that the yearly rate is $1125

The meaning of (f + g)(-1) is you substitute -1 to x of whatever polynomial you obtain after adding the polynomials f(x) and g(x).
                    f(x) + g(x) = -2x + 8 + 3x = x + 8
Substitute -1,
                        (f + g)(-1) = -1 + 8 = 7.
Thus, the answer is 7.