Answer:
The axis of symmetry is x = 6
Step-by-step explanation:
To find this, first find the two x-intercept values and then take the average. This will always be the line of symmetry.
x + 9 = 0
x = -9
x - 21 = 0
x = 21
Now take the average of these two numbers.
(-9 + 21)/2
12/2
6
The answer you want is going to be A
Hope it helps!!
we are supposed to explain
Which situation could be solved using the equation 
As we can see in the given equation , one number is -4 and the other number is 4
When we add two number of same value but opposite in sign we get zero.
This equivalent to the real life situation of paying a post paid bills.
Suppose you are using a post paid service , and the bills gets generated at the end of the month.
Suppose the bills amount is $x.
Once you pay that bills , then total outstanding again becomes $0.
Because 
Answer:
4
Step-by-step explanation:
Answer:
it is in quadratic equation meaning you use Plus or minus