Two years ago pete was three times as old as his cousin claire. two years before that, pete was four times as old as claire. in how many years will the ratio of their ages be 2 : 1 ?

the formula of a slope:

from a table we have

substitute:

the slope of f(x) is -1.

the graph of funcfion g(x) is a horizontal line. the slope of a horizontal line is equal 0. therefore the slope of g(x) is 0.

-1 < 0