Question

The population of Luis’s city in 2005 was 7400 and the population in 2010 was 9000. Let x represent the number of years since 2005. Which linear equation, in slope-intercept form, represents the population, y, at a year since 2005, x, where y is in thousands.

Answer 1

Answer:

The linear equation is;

y = 320x + 7400

Step-by-step explanation:

Here, we want to write a linear equation that represents the population y at a year since 2005

To write this, we need points

Initially, we have (0,7400)

Since the difference between 2005 and 2010 is 5, the second point will be (5,9000)

Mathematically, we can get the slope as follows;

m = (y2-y1)/(x2-x1) = (9000-7400)/(5-0) = 1,600/5 = 320

The equation of the line can be represented using the general form as;

y = mx + b

where m is 320 and b is unknown

So we have the equation as;

y = 320x + b

we need to get b

To get b, we can use any point

let us use the point (0,7400)

substituting this;

7400 = 320(0) + c

c = 7400

so the equation is;

y = 320x + 7400