X=3
PT=18
Steps:
4x+6=9x-9
Add 9 to 6 and subtract 4x from 9x
15=5x
3=x
Plug 3 into equation
12+6=18
Answer:
c.vertical angle is the answer
The diagonals bisect each other
To write the number is standard form we need to move the decimal point six times to the right, then:

therefore the answer is b.