How many four-letter permutations can be formed from the first five letters of the alphabet?

b. 153 students do not participate in sports and seventy-five 12th graders were surveyed

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!

step-by-step explanation: the answer for wha if rt is 10 centimeters long, and wha is st? it’s 6