Iswear these are impossible! me out

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.

answer: qc and de are congruent

hope i ! : )

during a tunnel construction project, engineers used explosives to excavate partway into a mountain. but due to constraints and environmental concerns, they later introduced a tunnel boring machine (tbm) to excavate the rest of the tunnel. the length and of the completed tunnel (in feet) is based on the number of days since the tbm started working. the length can be calculated using the equation y = 25x + 225. what does the y-intercept represent in this scenario?