Answer:
(a)
(b)
(c)
Step-by-step explanation:
We are required to construct 3 linear equations starting with the given solution z = 1/3.
<u>Equation 1</u>
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Multiply both sides by 9

Rewrite 3 as 5-2
9z=5-2
Add 2 to both sides
Our first equation is: 
<u>Equation 2</u>
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Multiply both sides by 21

Rewrite 7 as 11-4
21z=11-4
Subtract 11 from both sides
Our second equation is: 
<u>Equation 3</u>
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Multiply both sides by 6

Rewrite 6z as 4z+2z
4z+2z=2
Subtract 2z from both sides
Our third equation is: 
Regular shape with six sides: That is a Hexagon
Sum of angles in a regular Polygon is: (n - 2)*180
Where n = Number of sides
For Hexagon, n = 6.
Sum = (n - 2)*180
= (6 - 2)*180 = 4 * 180 = 720°
Answer: C & E
40% is equal to 0.4 as a decimal. As a fraction it is equal to 2/5 in simplest form.
In order to find the present you would have to multiple one of the numbers above by the initial value 84.
If you would like further explanation let me know. :)