Please help this question is hurting my brain

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?

My final challenge question of the day! i have no tests, nothing to do this for, it is simply giving away free points for a you tube video! so 50 free points for answering the most simple question ever! here is the key to getting brainiest for this question. answer in under 50 seconds. you think you can do it. i think you can. here is the question: 1x2= i know! easiest question ever! and yes! if you answer this question, you will be on you so come on and get the free 50 while you can!

How many times larger is 9 × 10^8 than 3 × 10^-5? a. 3 × 10^13 b. 3 × 10^-40 c. 3 × 10^-13 d. 3 × 10^3