I'm not quite sure what you asking here but if your asking how to answer it in "math terms" than I'll be happy to explain :)
So "times" means multiply and "increase" means add so righting this in math terms would be
6x + 5
because it's six times "a number" which you can replace with x!
Let me know if you have any questions :3
We know the perimeter is the total sum of all sides of the shape, we can use this to form an equation: the perimeter=1st side + 2nd side + 3rd side + 4th side 39a-7=9a+(5a+1)+(17a-6)+4th side.
Collect like terms to get 39a-7=31a-5+4th side
If we move everything but the 4th side over to the left we can solve
C. 8a-2=4th side is the correct answer
The domain of the function is 27 i am 100% sure
B.90 because 90 degrees is above the original angel