Question 409258
#1
a)
you are given 2 points which are (0,45000) and (3,39750)
2 points are all you need to plot a straight line.
{{{(P - 39750) / (t - 3) = (45000 - 39750) / (0 - 3)}}} (point-slope formula)
{{{(P - 39750) / (t - 3) = 5250/(-3)}}}
Multiply both sides by {{{-3*(t - 3)}}}
{{{-3*(P - 39750) = 5250*(t - 3)}}}
{{{-3P + 119250 = 5250t - 15750}}}
{{{-3P = 5250t -135000}}}
{{{P = -1750t + 45000}}}
--------------------
b)
The y-intercept is the population in 1990, at {{{t=0}}}
which is 45,000
c)
Solve for {{{P}}} at {{{t = 5}}}
{{{P = -1750*5 + 45000}}}
{{{ P = 36250}}}
---------------------
#2
a)
Here again you have 2 points, (9,4.4) and (12,3.6)
{{{(y - 3.6)/(x - 12) = (4.4 - 3.6) / (9 - 12)}}}
{{{(y - 3.6) / (x - 12) = .8/(-3)}}}
{{{(-3)*(y - 3.6) = .8*(x - 12)}}}
{{{-3y + 10.8 = .8x - 9.6}}}
{{{-3y = .8x - 20.4}}}
{{{ -30y = 8x - 204}}}
{{{y = (-4/15)*x + 6.8}}}
-------------------
b)
The y-intercept is millions of figures made in 1990, 6.8 million
c)
{{{y = (-4/15)*x + 6.8}}}
{{{y = (-4/15)*15 + 6.8}}}
{{{y = -4 + 6.8}}}
{{{y = 2.8}}}
2.8 million figures should be released in 2005