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 - 5y = 9a - 9y - 1
7a = 9a - 9y - 1 + 5y
7a - 9a = -9y - 1 + 5y
-2a = -4y - 1
a = \( \frac{-4y - 1}{-2} \)
a = \( \frac{-4y}{-2} \) + \( \frac{-1}{-2} \)
a = 2y + \(\frac{1}{2}\)

The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 67° - 70° = 43°

The area of a triangle is equal to ½ base x height:

a = ½bh
a = ½ x 1 x 6 = \( \frac{6}{2} \) = 3

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).

A parallelogram is a quadrilateral with two sets of parallel sides. Opposite sides (a = c, b = d) and angles (red = red, blue = blue) are equal. The area of a parallelogram is base x height and the perimeter is the sum of the lengths of all sides (a + b + c + d).