Recall your d = rt, distance = rate * time.
notice, the distance are the same, say it was "d" miles.
and if car A is travelling at a speed of say "r" mph, then B is going at "r+15" mph.

how far is B going? well, r + 15.
He first two are relatively easy. f(x-2) shifts it sideways (2 to the right in this case) f(x) -2 shifts it straight down (by 2)
f(2x) means replace x with 2x in the original 4(2x + 1)^2 − 3 if you factor out the 2 from the square root you get 4*sqr(2) ( x + ½)^2 - 3 which is now in the form a ( x -h)^2 + k the vertex is now at (-½, -3) (it used to be at (-1,-3) the "a" has gotten bigger, which makes the parabola "skinnier" (it goes up faster)
2•f(x) becomes 2*( 4(x + 1)2 − 3 ) = 8 (x+1)^2 -6 where is the vertex now? is this parabola fatter or skinnier than the original f(x) ?