The length of a rectangular is 5/2 unites greater then twice its width if it’s width w which expression gives the perimeter of the rectangle in terms w

If width is w the length can be represented as 5/2+2w.

Formula for perimeter is 2l + 2w

So it would be 2w + 2(5/2 + 2w)

OR 2w + 5 + 4w

OR 6w + 5

See if this helps ;)

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.