3(x+4)=9
3x+12=9
3x=-3
x=-1
Hope this helps :D
Answer:
A(2,2)
Step-by-step explanation:
Let the vertex A has coordinates 
Vectors AB and AB' are perpendicular, then

Vectors AC and AC' are perpendicular, then

Now, solve the system of two equations:

Subtract these two equations:

Substitute it into the first equation:

Then

Rotation by 90° counterclockwise about A(2,2) gives image points B' and C' (see attached diagram)
To find the mean all you have to do is add all the numbers...
you should get -30
and divide by a number of numbers, there are 6
so -30/6 is -5
Answer: Q1 is the 2
Step-by-step explanation: