SOLUTION: just started pre-ap math and need just some advice as parents are a bit out-dated with the new math I got one answer, my dad another and my mom another so please help --thanks

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Question 897530: just started pre-ap math and need just some advice as parents are a bit out-dated with the new math
I got one answer, my dad another and my mom another so please help
--thanks
-3/4+1/5+2/9=??

Found 2 solutions by lwsshak3, MathTherapy:
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
-3/4+1/5+2/9=??
change each fraction so they have a common denominator (don't have to be the lowest)
use the product of the 3 denominators for a common denominator=4*5*9=180
divide each denominator into 180 and multiply the numerator by this answer.
For example: 180/4=45: 3*45=135=numerator
-135%2F180%2B36%2F180%2B40%2F180=-59%2F180
sorry, I thought the procedure would be simpler to explain.
For problems with fractions like these, the idea is to find a common denominator for each fraction so you can just add the numerators to get the answer.

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!
just started pre-ap math and need just some advice as parents are a bit out-dated with the new math
I got one answer, my dad another and my mom another so please help
--thanks
-3/4+1/5+2/9=??

-+3%2F4+%2B+1%2F5+%2B+2%2F9
You need to determine the least common denominator (LCD). In this case, it is: 180
-+3%2F4+=+-+%283%2A45%29%2F%284%2A45%29 = -+135%2F180
1%2F5+=+++%281%2A36%29%2F%285%2A36%29 = +++36%2F180
2%2F9+=+++%282%2A20%29%2F%289%2A20%29 = +++40%2F180
Thus, -+3%2F4+%2B+1%2F5+%2B+2%2F9 becomes: -+135%2F180+%2B+36%2F180+%2B+40%2F180, or %28-+135+%2B+36+%2B+40%29%2F180_____highlight_green%28highlight_green%28-+59%2F180%29%29