The mileage is the independent variable. You can control it. The gasoline remaining DEPENDS ON the number of miles different. That's why it's called the dependent variable. It's change depends on the change in the independent variable
#9. There are 180 degrees in a triangle. We already know two of the sides which added together make 112. Then we do, 180-112=68
#10. We do the same process. 90 + 60 = 150
150-180= 30
#11. To find whether or not any three numbers can make a triangle, two of the numbers must equal more than the remaining number. But this has to be the case for any combination. 6+7=13. 13 is larger than 11. So yes it can.
#12. 8+2=10 which may be bigger than 6 but, 6+2=8. Which is equal to 8. So no, it cannot make a triangle.
I’m still working out the first question