Need by today!
sterling silver is an alloy of 92.5% silver and 7.5% copper by weight. you have 15 ounces of 800 grade silver which is 80% silver and 20% copper. how much pure silver should you add to the 800 grade to make sterling silver?

is the equation for copper 0.075(15 + s) = 3 + s?

Rectangle leg this 11feet and perimeter of 38feet what is the width of the rectangle in feet

What is x and y intercepts for y=x+7

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?