The only rule to follow is
Divide dividend by divisor and the mention the quotient and things left after remains in place of remainder
Here is a sample

Answer:

Step-by-step explanation:
1) Add 6 to both sides.

2) Simplify 21 + 6 to 27.

3) Divide both sides by 9.

4) Simplify 27/9 to 3.

<u>Therefor</u><u>,</u><u> </u><u>the</u><u> </u><u>answer</u><u> </u><u>is</u><u> </u><u>option</u><u> </u><u>B</u><u>.</u><u> </u><u>x</u><u> </u><u>></u><u> </u><u>3</u>.
Answer:
p = ½ (x₁ + x₂)
q = a (x₁x₂ − ¼ (x₁ + x₂)²)
Step-by-step explanation:
y = a (x − x₁) (x − x₂)
Expand:
y = a (x² − x₁x − x₂x + x₁x₂)
y = a (x² − (x₁ + x₂)x + x₁x₂)
Distribute a to the first two terms:
y = a (x² − (x₁ + x₂)x) + ax₁x₂
Complete the square:
y = a (x² − (x₁ + x₂)x + ¼(x₁ + x₂)²) + ax₁x₂ − ¼ a(x₁ + x₂)²
y = a (x − ½ (x₁ + x₂))² + a (x₁x₂ − ¼ (x₁ + x₂)²)
Therefore:
p = ½ (x₁ + x₂)
q = a (x₁x₂ − ¼ (x₁ + x₂)²)
800
You would multiply 10x80