Answer:
Option A - 
Step-by-step explanation:
We have given the expression 
We have to find the value of the expression ?
Solution :
Step 1 - Write the expression

Step 2 - Applying symbol rule i.e. multiplication of positive into negative is always negative, 

Step 3 - Solve

Therefore, The value of the expression is 
So, Option A is correct.
The quadratic formula is above.
You want each equation in standard form: ax^2 + bx + c = 0
I begin each problem by defining variables.
For instance 3. Is in standard form. X^2 -2x - 3 = 0. a = 1, b = -2, c = -3
Now use quadratic formula: x = [- b + or - sqrt(b^2 - 4ac)]\2a
Answer:
4/15
Step-by-step explanation:
The total number of spins completed is 6+8+7+9 = 30
The letter B came up 8 times
P(B) = number of B's over total
P(B) = 8/30 = 4/15