math140 homework problem!

[emilyj]

This problem seems super easy, but for some reason I keep getting stuck. Anywaysss, here it is:

Use algebra to solve the equation 2/x + 3/2x=10 for x cannot equal zero.

I tried multiplying both sides of the equation by 2, making both denominators x, but I'm not sure if that is even right. Please help, I'm desperate!!

 

[Mrspi]

This problem seems super easy, but for some reason I keep getting stuck. Anywaysss, here it is:

Use algebra to solve the equation 2/x + 3/2x=10 for x cannot equal zero.

I tried multiplying both sides of the equation by 2, making both denominators x, but I'm not sure if that is even right. Please help, I'm desperate!!

Can you show us what you got after you DID that (multiply both sides by 2)?

And, if you have two fractions with the same denominator, you should be able to add them, right?

And, if you end up with something like

5/n = 12, and you know that n is not equal to 0, you could surely multiply both sides of the equation by n to get a "normal-looking" equation like 5 = 12n and you could finish from there, right?

Please show us some further efforts, and let us know where you get stuck.

 

[emilyj]

Oh wow, I understand now. I was getting confused after I added the fractions and ended up with 5/x=20, but I just multiplied both sides by x, then divided by 20. Thank you so much for your help!

 

[Mrspi]

Oh wow, I understand now. I was getting confused after I added the fractions and ended up with 5/x=20, but I just multiplied both sides by x, then divided by 20. Thank you so much for your help!

I asked to see what you had after you multiplied by 2 because I was afraid you'd make the mistake you apparently DID make if you have 5/x = 20

2/x + 3/(2x)= 10

Multiply both sides by 2:

2*(2/x) + 2*3/(2x) = 2*10
4/x + 3/x = 20

Ok...you won't get 5/x on the left side. But you should be able to finish it now.