Find b and c so that y = 15x2 + bx+c has vertex (6, – 6).
b=
C =

step-by-step explanation:

mean or average is 40.6

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.

the answer is 6

hope this !