9/8 is in the simplest form
Bisects means to separate in equal parts, meaning each part is equal. This means the equations on each side of the line are equal. Once you equate them, you combine like terms finding your answer.
1) 2x+ 3=x+7
-x -x
x+3 = 7
-3 -3
Answer: x=4 (do this for the others)
2) x=7/2
3) x=5/2
21 containers for the ice cream
All you have to do is plug in the given values into the given equation and evaluate.
The expression is,

But we have to analyze the problem carefully. This is a natural phenomenon that can be modelled by a decay function. The reason is that, after every hour we expect the medicine in the blood to keep reducing.
Therefore we use the decay function rather. This is given by,

where,


and

On substitution, we obtain;


Now, we take our calculators and look for the constant

,then type e raised to exponent of -1.4. If you are using a scientific or programmable calculator you will find this constant as a secondary function. Remember it is the base of the Natural logarithm.
If everything goes well, you should obtain;

This implies that,

Therefore after 10 hours 24.66 mg of the medicine will still remain in the system.
I think you meant qualities