X+3y=18 3x+9y=12 determine weather the graphs of each pair of equations are parallel, perpendicular, coinciding, or none of these

The two lines are parallel.

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet

8

step-by-step explanation:

this is a subtraction problem.

10 - 2 = 8