A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

The perimeter of a triangle is the sum of the lengths of its sides:

p = x + y + z
p = 8cm + 10cm + 10cm = 28cm

To solve this equation, isolate the variable for which you are solving (c) on one side of the equation and put everything else on the other side.

2c + 3y = 9c + 9y - 2
2c = 9c + 9y - 2 - 3y
2c - 9c = 9y - 2 - 3y
-7c = 6y - 2
c = \( \frac{6y - 2}{-7} \)
c = \( \frac{6y}{-7} \) + \( \frac{-2}{-7} \)
c = -\(\frac{6}{7}\)y + \(\frac{2}{7}\)

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

5a + 2a = 7a