7.5 is already in decimal form.
6n=11c=-8j+5
Just combine the terms!
Answer:

Step-by-step explanation:
This half life exponential decay equation goes by the formula:

Where

Since half life is given as 22, we plug that into "Half-Life" in the formula for k and then plug in the formula for k into the exponential decay formula:
So,

Now

third choice is correct.
the answer is 11/4
The unit rate of change between variables is the quotient between the difference between y-values and the difference between x-values