Algebra

the surface area of a sphere is a=4 pie r squared where r is the radius of the sphere. waht is the radius, rounded to the nearest tenth, of a ball with surface area equal to 85 square inches? below the question is A. 2.6 in. B 6.8 in. C. 2.7 in. D 6.7 in.

85=4(pi)(r^2). Divide each side by 4 to get 21.25=(pi)(r^2). Then divide pi from both sides, so you get (r^2)=6.76... Take the square root of each side so the radius=2.6 inches.

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asked by kati

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