If x=2, calculate the value of: x^3-x

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?

In which direction does the left side of the graph of this function point? a(x) = 3x - x2 + 4x - 2