The 4th term is 135
n-1
you get it by using the formula Tn= ar <span />
9) C.
10)A.
11) $75
Those are all the answers that you needed.
Answer:

Step-by-step explanation:
Isolate the variable, a. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
PEMDAS is the order of operation and stands for:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
First, add 3 to both sides of the equation:
u = -3a - 3
u (+3) = -3a - 3 (+3)
u + 3 = -3a
Next, divide -3 from both sides of the equation:
(u + 3)/-3 = (-3a)/-3
a = (u + 3)/-3
is your answer.
~