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-4/5x=16/15

fractions are killing me, help
 
 

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Jason S. | My goal is the success of my students. Knowledge-Patience-HonestyMy goal is the success of my students. K...
4.9 4.9 (115 lesson ratings) (115)
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If it's this:
-4/(5x) = 16/15
 
You can cross-multiply:
-4 * 15 = 5x * 16
-60 = 80x
 
Divide by 80:
-60/80 = x
x = -3/4
 
 
If it's this:
(-4/5)x = 16/15
 
As stated above by Bill:
Multiply both sides by -5/4.
x = (16/15) (-5/4)
 
Cancel 16 and the 4.
 
x = (4/15)(-5/1)
 
Cancel the 15 and the -5
 
X = (4/3)(-1/1)
x = -4/3
 
Notice the answers are reciprocals depending on whether the x is in the numerator or the denominator.
 
Helpful suggestion:
Please make liberal use of parentheses when posting your questions.
 
 
Hope this helps.
Jason

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Bill W. | Looking for help with Excel, SQL, or other business technology?Looking for help with Excel, SQL, or oth...
4.9 4.9 (36 lesson ratings) (36)
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Hi Amy!  As you know, you're trying to solve for x, so you need to isolate the x.  That means moving the -4/5 from the left side over to the right side.
 
1.  To get rid of the -4/5, you can divide -4/5x by -4/5.  This leaves you with 1x, or simply x.
 
       -4/5x   =  x
       -4/5
 
2.  However, whatever you do to one side of the = sign you have to do to the other.  Therefore, since you divided the left side by -4/5, you have to divide the right side by -4/5.  In other words, x = 16/15 divided by -4/5.
 
3.  Remember the rule for dividing fractions:  Flip the fraction you want to divide by, then multiply the fractions.
 
       16  รท  -4     =    16  x   5
       15       5            15  x  -4
 
When you do that math, you'll have the answer for x.  You'll probably want to simplify the result.  Hope this helps!
 
Bill W.