A math teacher said that 18 out of 25 students passed the test what percent did not pass the test

28%

Step-by-step explanation:

18/25=.72 ->72% passed the test, so then we take 100 and subtract 72 from it which leaves us with 28% that did not pass the test

28% of students did not pass.

Step-by-step explanation:

18/25 = 72/100

72% passed.

So, if 18/25 students passed, (72%) then 7/25 students did not pass (28%)

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

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!