How many faces, edges and vertices are found in a cube?
If you observe a cube, you will find 6 faces, 8 vertices, and 12 edges. It can be tricky, trying to count these qualities of any three dimensional shape; I suggest drawing the shape, and marking them as you count.
Combine the following terms to simplify the expression: -10x + (-5x)
-15x. -10(x) + -5(x) Adding a negative is the same as subtracting: -10(x) - 5(x) Starting at negative ten and subtracting five more results in -15x. Like terms can be combined by adding or subtracting their coefficients. In this case, we added a negative coefficient  from another negative coefficient, .
What is Newton's third law of motion?
For every action, there is an equal, but opposite reaction. If I were to inflate a balloon, then let it go, the force of the air blowing out causes the balloon to propel forward. The force of releasing air is - in a perfect world, closed-system scenario - equal, and opposite the direction of the force moving the balloon.