Answer:
5
Step-by-step explanation:
this is basic algebra so it's important to understand this concept now. you need to combine like terms so 3x-6=9 becomes 3x=15 (you add the 6 to add like terms). You then divide the 3 from 3x on both sides to get x=5
see picture for steps
x= 10
Multiply by the inverse of the coefficient of r², then take the square root.
For V=50, h=15, this is ...
4.38 / 0.5 = 8.76
Hope it helps :D