SOLUTION: Balancing Equations Using Multiplication cannot figure out how to do this with negatives... {{{-4x/3}}} = {{{18/5}}} the negative is in front of both numbers in the first fracti

Algebra ->  Exponents-negative-and-fractional -> SOLUTION: Balancing Equations Using Multiplication cannot figure out how to do this with negatives... {{{-4x/3}}} = {{{18/5}}} the negative is in front of both numbers in the first fracti      Log On


   

Question 118618: Balancing Equations Using Multiplication
cannot figure out how to do this with negatives...
-4x%2F3 = 18%2F5
the negative is in front of both numbers in the first fraction.
must solve equation and also show checks
Found 3 solutions by ankor@dixie-net.com, Earlsdon, Edwin McCravy:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Assume you mean:
-%284x%29%2F3 = 18%2F5
:
Get rid of the denominator and the negative x, multiply both sides by -15
-15*-%284x%29%2F3 = -15*18%2F5
:
Cancel the denominators and change the signs
+5(4x) = -3(18)
:
20x = -54
:
x = -54%2F20
Reduces to:
x = -27%2F10 or -2.7
:
:
Check solution in original equation
-%284%28-2.7%29%29%2F3 = 18%2F5
%28%2B10.8%29%2F3 = 18%2F5
Using a calc
3.6 = 3.6; confirms our solution of x = -2.7

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve for x:
-%284%2F3%29x+=+18%2F5 Multiply both sides by the multiplicative inverse of -%284%2F3%29 which is -%283%2F4%29
%28-3%2F4%29%28-4%2F3%29x+=+%28-3%2F4%29%2818%2F5%29 Simplify.
x+=+-54%2F20
x+=+-27%2F10
Check:
%28-4%2F3%29x+=+18%2F5 Substitue x+=+-27%2F10
%28-4%2F3%29%28-27%2F10%29+=+18%2F5 Simplify.
108%2F30+=+18%2F5 Reduce the fraction on the left side.
18%2F5+=+18%2F5

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
cannot figure out how to do this with negatives...
-4x%2F3 = 18%2F5
the negative is in front of both numbers in the first fraction.
must solve equation and also show checks

-4x%2F3 = 18%2F5

Get rid of that negative sign on the left by using this rule:

You can change the sign of EVERY TERM on both sides of an
equation and the resulting equation will be equivalent:

So we change the sign on the left to positive and we
change the sign on the right side to negative.

4x%2F3 = -18%2F5

So multiply both sides by 3%2F4

3%2F44x%2F3 = -18%2F53%2F4

Cancel the 3's and 4's on the left.
Multiply numerators and denominators on the right:

%28cross%283%29%29%2F%28cross%284%29%29%28cross%284%29x%29%2F%28cross%283%29%29 = -54%2F20

Reduce the fraction on the right:

x = -27%2F10

To check, it is easier to write -27%2F10 as a decimal -2.7

-4x%2F3 = 18%2F5

-%284%28-2.7%29%29%2F3 = 18%2F5

-%28-10.8%29%2F3 = 18%2F5

The negatives cancel on the left.
Change 18%2F5 on the right to decimal 3.6


10.8%2F3 = 3.6

Divide the left side:

3.6 = 3.6

Edwin