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 equal sign and the answer on the other.

-3z + 5 = \( \frac{z}{-9} \)
-9 x (-3z + 5) = z
(-9 x -3z) + (-9 x 5) = z
27z - 45 = z
27z - 45 - z = 0
27z - z = 45
26z = 45
z = \( \frac{45}{26} \)
z = 1\(\frac{19}{26}\)

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.

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

-7a + y = -9
y = -9 + 7a

then substitute the result (-9 - -7a) into the second equation:

7a + 2(-9 + 7a) = 4
7a + (2 x -9) + (2 x 7a) = 4
7a - 18 + 14a = 4
7a + 14a = 4 + 18
21a = 22
a = \( \frac{22}{21} \)
a = 1\(\frac{1}{21}\)

The volume of a cylinder is πr²h:

v = πr²h
v = π(2² x 3)
v = 12π

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

c = πd
c = π(2 * r)
c = π(2 * 17)
c = 34π