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

7a - 8y = a - 3y - 5
7a = a - 3y - 5 + 8y
7a - a = -3y - 5 + 8y
6a = 5y - 5
a = \( \frac{5y - 5}{6} \)
a = \( \frac{5y}{6} \) + \( \frac{-5}{6} \)
a = \(\frac{5}{6}\)y - \(\frac{5}{6}\)

A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

The formula for circumference is circle diameter x π. Circle diameter is 2 x radius:

c = πd
c = π(2 * r)
c = π(2 * 4)
c = 8π

The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.

To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:

a = s²

so the length of one side of the square is:

s = \( \sqrt{a} \) = \( \sqrt{64} \) = 8

The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:

c² = a² + b²
c² = 8² + 8²
c² = 128
c = \( \sqrt{128} \) = \( \sqrt{64 x 2} \) = \( \sqrt{64} \) \( \sqrt{2} \)
c = 8\( \sqrt{2} \)