Answer:
1. 
2. 
Step-by-step explanation:
Given
Variation: inverse Proportion
y = 7, x = 9
Required
- Write an equation connecting y and x
- Find y when x = 21
Given that thee variation is inversely proportional;
This implies that

Convert variation to equation
----------- Equation 1
Where k is the constant of variation
Substitute 7 for y and 9 for x in equation 1

Multiply both sides by 9


Substitute 63 for k in equation 1

Multiply both sides by x


Hence, the equation connecting x and y is 
Solving for when x = 21
Substitute 21 for x in the above equation

Divide both sides by 21


Answer:
54 and 30
Step-by-step explanation:
84÷2=42-12=30
42+12=54
= (16x3 - 8x2 + 4x4) / 2x
= 4x * (4x2 - 2x + x3) / 2x
= 2 * (4x2 - 2x + x3)
= 8x2 - 4x + 2x3
Answer A
I believe the answer is C