Answer:
The relationship between the circumference of a circle and its diameter represent a direct variation and the constant of proportionality is equal to the constant 
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form 
where K is the constant of proportionality
In this problem we know that
The circumference of a circle is equal to

therefore
the relationship between the circumference of a circle and its diameter is a direct variation and the constant of proportionality is equal to the constant 
(8)(2)+4(8)(-5)(2)(2)
The answer is -624
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Answer:
x = 3
Step-by-step explanation:
We need it in factorized form to get x.
If the quadratic equation can be divided by a-2 the first part is:
(a-2)
Now to get a², the a must be multpilied by itself. So
(a-2)(a)
To get -10, -2 must be multiplied by 5. So:
(a-2)(a+5)
we can expand to get x
a² + 5a - 2a -10
a² + 3a - 10
a² + ax - 10
x = 3