You need to find the value of a so solve the first equation in terms of z:

7a + z = -2
z = -2 - 7a

then substitute the result (-2 - 7a) into the second equation:

2a - 8(-2 - 7a) = -9
2a + (-8 x -2) + (-8 x -7a) = -9
2a + 16 + 56a = -9
2a + 56a = -9 - 16
58a = -25
a = \( \frac{-25}{58} \)
a = -\(\frac{25}{58}\)

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.

2b + 3 > 1 + b
2b > 1 + b - 3
2b - b > 1 - 3
b > -2

A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.

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).

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.