The angle is 90 degree...
Answer:
-1
Step-by-step explanation:
The common difference is the constant amount of change between the numbers in an arithmetic sequence.
To find the common difference, you take the last term and subtract it by the previous term.

So youve done good so far.
So picking up from : (x^2-x-12)-2(x-4)
-First distribute the (-2) to each factor.
(x^2 - x - 12) -2x + 8
-Then just add variables with the same exponent
x^2 - 3x - 4
Done!
An irrational number like pi