Answer:
the greatest common factor of 10 and 70 is 10
When you have two lines in an x shape, vertical angles are the ones opposite each other.
in the example here, the angles with the purple dots are vertical angles and the angles with the blue dots are the other vertical angles
15x2+10x-9x+7
8x3+20x2+3x+12
11x4+4x2-6x2-16
Hope this helps !!
8*(n+6)=80
distribute
8n+48 = 80
subtract 48 from each side
8n = 32
divide by 8
n=4
Answer: 8.72
hoped this helped