anonymous one year ago In 1980, the U.S. has 5.6% of the world's population. By 1990, the percent had dropped to 5.2%.Assuming the population continues to fall at the same rate, write a linear equation that expresses the U.S. percent of the world's population, y, in terms of the year, x.

1. anonymous

@Astrophysics

2. anonymous

in 10 yrs it goes down 4%

3. Astrophysics

Hey

4. anonymous

hey

5. Astrophysics

We can write it in y = mx+b form, which is the equation of a line

6. anonymous

im following

7. Astrophysics

So the crucial information which will give us our slope is (5.6%, 1980) and (5.2%, 1990) where the percents can be written as 5.6% = 0.056 and 5.2% = 0.052, we can use this to find the slope, using the formula I showed you a while ago $m= \frac{ y_2-y_1 }{ x_2-x_1 }$ so here we can use the point slope formula once we find the slope $y−y_1=m(x−x_1)$

8. anonymous

then i just plug it in right?

9. Astrophysics

Yes find the slope first and then plug it into the point slope formula, once you plug in the point slope formula, set it up as y = mx+b format if you like, depending on your teacher.

10. anonymous

ok thank you so much

11. Astrophysics

Np