# Math

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The area of a circle is given by the expression pi(16x^2 - 40x + 25) .
a) What is the diameter of the circle?

b) What is its circumference?

• Math -

area= PI (4x-5)^2

but area= PI r^2
so r= 4x-5

diameter= 2*r

circumference= 2PI*r

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