Here, I'll do the first one for you.
When they are talking about a number, use "x".
Since it says twice a number, you say 2x. Or 3x for three times the number
2x+12=3x-31
Then use algebra to find x. Get the numbers on one side and all the x's on the other.
2x+12+31=3x-31+31
2x+43-2x=3x-2x
x=43
Now do the rest on your own!
Answer:
a. 
b. 
c. 
d.
minutos
Step-by-step explanation:
a. Newton's law of cooling states that the speed with which a body is cooled is proportional to the difference between its temperature and that of the medium in which it is found. Then, the initial value problem is given by:


b. The differential equation obtained is a differential equation of separable variables:

c. After 33 minutes of serving the coffee has cooled to 180°:

d.

V= 15 steps are down below
would the answers be 0.5? i'm not sure but i tried. have a great day.
cuz half (x2) of a number (x) is (=) one..
2x=1
0.5=x
0.5x2=1