Answer:
3z
Step-by-step explanation:
When you write a number followed by a variable with no operation in between them, it means multiplication.
3 multiplied by z is 3 * z, but you can write it without the multiplication sign simply as 3z.
Answer:

Step-by-step explanation:
The rate of change in the temperature T of coffee at time t is written as
(remember derivatives are used to express rates of change, and in our case the rate of change of the temperature T). The difference between the temperature M of the air at time t, and the temperature T of the coffee at time t can be expressed as 
Saying that the rate of change in the temperature T is proportional to the difference between M and T is just a way of saying that the rate of change in the temperature T is equal to the difference between M and T, multiplied by some constant k (whose value we don't know, but still that's what it means).
Therefore we get

Answer:
less than
Step-by-step explanation:
because
1 l= 1000 ml
so 4.2 l= 4.2x1000
= 4200 l
so 4200<4800
Answer:
x=0
Step-by-step explanation:
Answer:
Step-by-step explanation:
hello :
the n-ieme term is : An=A1×r^(n-1)
A1 the first term r : the common ratio
in this exercice : A1 =15 r = 1/3 n = 4
A4=15×(1/3)^(4) =15×4^4 =3840