Help! I'm having trouble with these fraction problems

[thatdarnbee13]

1. 3(y-2)/5=1-3y

2. -4/9x-(x-4/9)=1/81(x-1)

3. 3/5x+1/2=-2/5x-5/7

4. -1/3(x-9)-1/3(x-3)=x-4

If anyone can help. I did the problems..just want to make sure they're right.
Answer I got:
1. 11/18
2. 37/118
3. 17/12
4. 24/5

 

[Denis]

3. 3/5x+1/2=-2/5x-5/7
3. 17/12

All correct except #3: you get a 75% mark :wink:

Easier if you rewrite these this way:

3x/5 + 1/2 = -2x/5 - 5/7 : now you can CLEARLY "see" the denominators; kapish?

Multiply by LCM of 70:
42x + 35 = -28x - 50 : that'll end up x = -17/14

Btw, you can check your answers yourself, by substituting back in the original equation :idea: