If y varies directly as x, and y is 18 when x is 5, which expression can be used to find the value of y when x is 11? A. Y = 5/18(11)
B. Y = 18/5(11)
C. Y = (18)(5)/11
D. Y = 11/(18)(5)

How do you solve a question like this?

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?

For the feasibility region shown below find the maximum value of the function p=3x+2y