3. ΔPQR ≅ ΔSRT
3. ASA (Angle - Side - Angle) - we have two triangles where we know two angles and the included side are equal
If two sides and the included angle of one triangle are equal to the corresponding sides and angle of another triangle, the triangles are congruent.
4. PR ≅ SR
4. ΔPQR ≅ ΔSRT - the corresponding sides are congruent.
Answer:
a. 
b. 
Step-by-step explanation:
First, we need tot find a general expression for the amount of caffeine remaining in the body after certain time. As the problem states that every hour x percent of caffeine leaves the body, we must substract that percentage from the initial quantity of caffeine, by each hour passing. That expression would be:

Then, to find the amount of caffeine metabolized per hour, we need to differentiate the previous equation. Following the differentiation rules we get:

The rate is negative as it represents the amount of caffeine leaving the body at certain time.
X^2+5x=2
you then solve by completing the square using the formula (b/2)^2 in order to create the new term. Solve for x by using this term to complete the square.
Your answer is then
x=-5/2+-√33/2
So what you need to do is find the less he can use.
3a squared +4a-7 squared is a 2 btw