Answer:
5. D (4,6)
6. B (7.8)
Step-by-step explanation:
5. Add the two X coordinates (6+2) and divide that by 2 (8/2=4), do the same for the two Y coordinates (4+8=12, 12/2=6)
6. Use the distance formula 
Input the coordinates 
160/80=2, and 150/30=5 so he earns 3 more points from gold stars than silver stars
P=18 because 3 times two is 6 and 4 times 3 is 12 so when you add them you get 18
Answer:
+5.20 µC
Explanation:
Given that
Charge =−5.20 µC and radius= 5.40 cm.
Insert a +10.4- µC charge at the center of the sphere
As we know that according to Gauss's theorem electric field inside the metal is zero.
When +10.4 µC charge insert but the total charge on the sphere should be −5.20 µC.So the charge on the outer surface of the sphere will be +5.20 µC.