Register to reply 
How do I solve an equation with a variable in the numerator? 
Share this thread: 
#1
Sep1311, 02:29 PM

P: 49

1. The problem statement, all variables and given/known data
I just missed a 16point question on a quiz because I didn't know how to separate the variable. It was an absolute value equation, but I just need to know how to deal with a variable in a fraction. Here's what it looked like: 2. Relevant equations (5x+10)/2 = 20 3. The attempt at a solution I tried multiplying everything by the denominator, but I'm not sure if or why that works. Any help would be greatly appreciated, thanks! 


#2
Sep1311, 02:32 PM

Admin
P: 23,701

Multiplying by denominator should work. You can do anything that doesn't change the equality  that means adding, subtracting, multiplying or dividing both sides of the equation by the same thing.
Or you could write the fraction as [itex]\frac {5x}{2} + \frac {10}{2}[/itex]. 


#3
Sep1311, 04:02 PM

P: 49

Thanks!



#4
Sep1611, 01:33 AM

P: 2

How do I solve an equation with a variable in the numerator?
The easiest way is to multiply both sides of the equation by the denominator. The reason why this works is because it doesn't change the equality.
(5x+10)/2 = 20 5x+10 = 40 5x = 30 x = 6 Even if the variable was in the denominator, you can still solve for the variable using the same steps. 2/(5x+10) = 20 2 = 100x + 200 198 = 100x 198/100 = x x = 99/50 


Register to reply 
Related Discussions  
How do I solve an equation with a fraction as the variable's coefficient?  Precalculus Mathematics Homework  6  
Nonlinear ODE: Use change of variable to solve the equation for initial conditions  Calculus & Beyond Homework  1  
Double variable equation how to solve?  Precalculus Mathematics Homework  6  
How do you solve an equation with the variable in the denominator  Calculus & Beyond Homework  1  
Solve for the variable?  Precalculus Mathematics Homework  3 