All numbers less than or equal to 87 and greater than or equal to 83

Step-by-step explanation:

Split the words at "and" and solve one piece at a time. (when a function has "or equal to", use the ones with the line under ) Let x be the unknown value

"less than or equal to 87"

"greater than or equal to 83"

Put them together by putting x in the middle. Don't forget to make the signs face the right way:

Done.

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)

5 pm

step-by-step explanation: