When Xavier runs the 400 meter dash, his finishing times are normally distributed
with a mean of 61 seconds and a standard deviation of o.5 seconds. If Xavier were to
run 34 practice trials of the 400 meter dash, how many of those trials would be
slower than 62 seconds, to the nearest whole number?

{3 + i, 3 - i, 3, -1}

step-by-step explanation:

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8

there is only one way to arrange all the eight relative to each other because they are not distinct. we have

now there are nine places to place an (and not more than one in one place).   because we have four symbols, we need to choose four of these nine places to insert an . order does not matter because the are not distinct.

thus there are 1 · c(9,4) ways, or, if we calculate it,

thus there are 126 ways to form such "words."