D What is the Missing Step in this Electrostatic Algebra Equation?

AI Thread Summary
The discussion centers on a homework question regarding electrostatic seesaws and algebraic manipulation. The individual is confused about how a specific term cancels out in the equation. It is clarified that there is no missing step; rather, two fractions with a common denominator can be combined. The example provided illustrates that adding fractions with the same denominator is straightforward. Understanding this concept resolves the confusion regarding the algebraic process.
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Homework Statement



I have a homework question on electrostatic seesaws. My problem is the algebra.

Homework Equations



I have been following another example and any guidance to help me proceed would be great.

0= (2q Q)/(4πε_o r²)+(q Q)/(4πε_o r²)-m
0= (3q Q)/(4πε_o r²)-m
m=(3q Q)/(4πε_o r²)

I don't understand line 2. I don't understand how part of the equation has canceled out. I know there is a step missing so could anyone point me in the right direction.

The Attempt at a Solution

 
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There is no step missing.

There are two fractions which are the same, therefore they can be added:
\frac{2x}{y} + \frac{x}{y} = \frac{3x}{y}
 
Of course! Thank you compuchip x
 
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