Answer:
2n +10= 140
4n- 40= 80
2n= 3n - 20
Step-by-step explanation:
it is the am progression or sum progression
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.
35 50 65 I have to type more because it doesn’t let me answer if I don’t
Answer:
x = 10 cm
Step-by-step explanation:
(3x + 2) + (3x + 2) + (4x - 5) + (4x - 5) = 134 cm
combine like terms:
14x - 6 = 134
add 6 to each side of the equation:
14x = 140
divide both sides by 14:
x = 10