18 = 10 + 2k
move 10 to the other side
sign changes from +10 to -10
18-10=10-10+2k
18-10= 2k
8= 2k
divide by 2 to get k by itself
8/2= 2k/2
Cross out 2 and 2 , divide by 2 and then becomes 1*1*k= k
k=8/2
Answer: k= 4
Answer: x = 6
<u>Step-by-step explanation:</u>
2[3x - (4x - 6)] = 5(x - 6)
2[3x - 4x + 6] = 5x - 30
2[-x + 6] = 5x - 30
-2x + 12 = 5x - 30
<u>+2x </u> <u>+2x </u>
12 = 7x - 30
<u>+30 </u> <u> +30 </u>
42 = 7x

6 = x
The equation that can be used to determine the volume of the sphere is 4/3π10³
<h3>What is the volume of the sphere?</h3>
A sphere is a three-dimensional object in which points from its center to its circumference is equidistant.
Volume of a sphere = 4/3πr³
Where:
To learn more about the volume of a sphere, please check: brainly.com/question/13705125