An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

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

7b + 2y = -5b - 3y + 7
7b = -5b - 3y + 7 - 2y
7b + 5b = -3y + 7 - 2y
12b = -5y + 7
b = \( \frac{-5y + 7}{12} \)
b = \( \frac{-5y}{12} \) + \( \frac{7}{12} \)
b = -\(\frac{5}{12}\)y + \(\frac{7}{12}\)

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 - 5a = 0a

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

x² + 4x - 21 = 0
(x - 3)(x + 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (x - 3) or (x + 7) must equal zero:

If (x - 3) = 0, x must equal 3
If (x + 7) = 0, x must equal -7

So the solution is that x = 3 or -7

The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 8 x 8) + (2 x 8 x 1) + (2 x 8 x 1)
sa = (128) + (16) + (16)
sa = 160