
Steve S. answered 04/07/14
Tutor
5
(3)
Tutoring in Precalculus, Trig, and Differential Calculus
E = (9/x + 7/x^2)/(5/y + 3/y^2)
Can’t divide by zero, so x≠0 and y≠0.
xy≠0 includes both.
Multiply right side by 1=(x^2y^2)/(x^2y^2):
E = (9x^2y^2/x + 7x^2y^2/x^2)
/(5x^2y^2/y + 3x^2y^2/y^2), xy≠0
E = (9xy^2 + 7y^2)/(5x^2y + 3x^2), xy≠0
E = y^2(9x+7)/(x^2(5y+3)), y≠0
[Try substituting y=0 in original and final E. The result should be the same, right?]
Can’t divide by zero, so x≠0 and y≠0.
xy≠0 includes both.
Multiply right side by 1=(x^2y^2)/(x^2y^2):
E = (9x^2y^2/x + 7x^2y^2/x^2)
/(5x^2y^2/y + 3x^2y^2/y^2), xy≠0
E = (9xy^2 + 7y^2)/(5x^2y + 3x^2), xy≠0
E = y^2(9x+7)/(x^2(5y+3)), y≠0
[Try substituting y=0 in original and final E. The result should be the same, right?]