Answer:
Step-by-step explanation:
The radius it .5 of the diameter so in this case the radius is 11. The formula for area is pi*r^2= pi*11^2=pi*121=380.13
There is no solution for the first one
if you eliminate y you get 2 equations
-13x - 13z = -25
-13x - 13x = -15
- there is no solution to theses
a23 means the element in the second row and the 3rd column
so its -5
Weird. I think you just need to look if the point falls on the shaded area. But only (-5,5) does ...