Road a is x miles long. road b is four miles shorter than road a, and road c is twice as long as road b. road d is twice as long as road a, and road e is 8 miles shorter than road d. write an expression for the length of each road in terms of x. which two roads must be the same length?

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?

What is the solution of the systems of equations? y=2/3x+3 x=-2

If the value of cos330°is√3/2 then find cos 165°.