SOLUTION: The area of a circle is given by the expression 16pix^2 -40pix +25pi Determine an expression for the circumference of this circle. sorry, I wasn't sure how to put the sign

Algebra ->  Distributive-associative-commutative-properties -> SOLUTION: The area of a circle is given by the expression 16pix^2 -40pix +25pi Determine an expression for the circumference of this circle. sorry, I wasn't sure how to put the sign      Log On


   

Question 1177919: The area of a circle is given by the expression 16pix^2 -40pix +25pi
Determine an expression for the circumference of this circle.
sorry, I wasn't sure how to put the sign for pie. and the x is supposed to be there after pi, just clarifying.
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

The area of a circle is given by the expression
16pi%2Ax%5E2+-40pi%2Ax+%2B25pi
since the area of a circle is r%5E2%2Api, we can use it to find r
=> r%5E2%2Api=16pi%2Ax%5E2+-40pi%2Ax+%2B25pi .......simplify

r%5E2=16x%5E2+-40x+%2B25+
r%5E2=%284x%29%5E2+-40x+%2B5%5E2
r%5E2=%284x+-+5%29%5E2
r=4x+-+5

then, the circumference of this circle 2r%2Api
and an expression for the circumference of this circle will be
2%284x+-+5%29pi
8x%2Api+-+10pi