The mexican tetra is a tropical fish that requires a water temperature between 68 and 77 degrees fahrenheit, inclusive. an aquarium is heated 8 degrees so that a tetra can live in it. what temperatures could the water have been before the heating?

The temperature of the water could have been between 60 and 69 degrees Fahrenheit(inclusive) before the heating.

Explanation

Suppose, the temperature of the water before the heating was degree Fahrenheit.

The aquarium is heated 8 degrees so that a Tetra can live in it. So, the current temperature of the water degree Fahrenheit.

Given that, Tetra requires a water temperature between 68 and 77 degrees Fahrenheit, inclusive. So.....

Thus, the temperature of the water could have been between 60 and 69 degrees Fahrenheit(inclusive) before the heating.

true? is that what you're asking or do you mean something else?

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)