The current population of a small city is 46000 people.

Question

The current population of a small city is 46000 people. Due to a loss of jobs, the population is decreasing by an average of 400 people per year. How many years (from now) will it take for the population to decrease to 42800 people?

A) Write an equation you can use to answer this question. Be sure all the numbers given above appear in your equation. Use x as your variable and use no commas in your equation.

The equation is   

B) Solve your equation in part [A] for x.

Answer: x=

Answer 1

Why make it more complicated than it needs to be?

Yr. Pop'n

0 46,000

1 45,600

2 45,200

3 44,800

4 44,400

5 44,000

6 43,600

7 43,200

8 42,800

Looks like it's at 42,800 at the end of the 8th year. Don't think the equation needs the "-1" component.

Answer 2

A) 42800 = 46000 - (x-1)400;

B) x - 1 = (46000 - 42800)/400 = 8; x = 9 years

.