SOLUTION: The edges of one Cube are 3 centimeters longer than the edges of another Cube. the total surface area of the first Cube exceeds the total surface area of the second Cube by 234 cen

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Question 1063379: The edges of one Cube are 3 centimeters longer than the edges of another Cube. the total surface area of the first Cube exceeds the total surface area of the second Cube by 234 centimeters squared. how long is each edge of the larger cube?
Tried 6e (e+3) = 6e squared +234 but i get 13. I know the answer is 8 but cant seem to work the equation correctly.

Answer by ikleyn(53765) About Me  (Show Source):
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The edges of one Cube are 3 centimeters longer than the edges of another Cube. the total surface area of the first Cube exceeds
the total surface area of the second Cube by 234 centimeters squared. how long is each edge of the larger cube?
Tried 6e (e+3) = 6e squared +234 but i get 13. I know the answer is 8 but cant seem to work the equation correctly.
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6(x+3)^2 = 6x^2 + 234   --->

(x+3)^2 - x^2 = 39,

x^2 + 6x +9 - x^2 = 39,

6x = 30   ---->  x = 5.


Smaller cube edge is 5. Larger cube edge is 8.