algebra 1
posted by layla .
In 1975, when the United Nations was formed, there were 51 member nations. In 1987, there were 159 member nations. Write an equation that gives the number of nations in the UN, y, in terms of the year, t. Let t=0 correspond to 1945 and assume that membership followed a linear pattern.

if t = 0 corresponds to 1945
then 1987 > 42
so think of it as two ordered pairs
(0, 51) and (42, 159)
slope = (15951)/(420) = 108/42 = 18/7
N = (18/7)t + b
but (0,51) would be the yintercept
N = (18/7) t + 51
Even though we can do the math, the question itself it ridiculous. Membership is not a linear function at all, it would be a "step function".
At present, there are about 200 countries, and according to our equation , that total was reached in about 2003, and the number of countries currently members of the UN would be 223