Which of the following is the image of D after a rotation of 90° about the origin? O (-2,1)
O (2.1)
O (-1,-2)
ODA

answer: the value of x is 7cm

step-by-step explanation:

idk

step-by-step explanation:

use that smart brain

first one because it can't have a fraction in it

step-by-step explanation:

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."