Abaker needs 4 3⁄4 cups of flour. if she uses a 1 1⁄2 cup measuring scoop, how many scoops of flour must the baker use to have at least 4 3⁄4 cups?

3 scoops and a quarter? not really sure if you were saying one and a half cups or if the Baker was using ONE half cup scoop

1 1/2+1 1/2+1 1/2+ 1/4 =4.75

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.