Solve for X in (3-x)/9 = (4+x)/6: Fraction Equation Practice

Question

Solve for X:


3x9=4+x6 \frac{3-x}{9}=\frac{4+x}{6}

Video Solution

Solution Steps

00:00 Find X
00:05 Multiply by the common denominator to eliminate fractions
00:19 Simplify as much as possible
00:34 Make sure to open parentheses properly, multiply by each factor
00:51 Arrange the equation so that one side only has the unknown X
01:18 Collect like terms
01:27 Isolate X
01:37 Simplify as much as possible
01:41 And this is the solution to the problem

Step-by-Step Solution

To solve the equation 3x9=4+x6 \frac{3-x}{9} = \frac{4+x}{6} , we will use the method of cross-multiplication to eliminate the fractions.

Step 1: Cross-multiply to get rid of the fractions. This involves multiplying the numerator of each fraction by the denominator of the other:

(3x)×6=(4+x)×9 (3-x) \times 6 = (4+x) \times 9

Step 2: Distribute the multiplication over the terms inside the parentheses:

6(3x)=9(4+x) 6(3-x) = 9(4+x)

186x=36+9x 18 - 6x = 36 + 9x

Step 3: Combine like terms to simplify the equation. Start by getting all the x x -terms on one side and the constant terms on the other:

  • Add 6x 6x to both sides: 18=36+9x+6x 18 = 36 + 9x + 6x
  • Rearrange: 18=36+15x 18 = 36 + 15x
  • Subtract 36 from both sides: 1836=15x 18 - 36 = 15x
  • Result: 18=15x -18 = 15x

Step 4: Solve for x x by dividing both sides by 15:

x=1815 x = \frac{-18}{15}

Therefore, the solution to the equation is x=1815 x = -\frac{18}{15} .

Answer

1815 -\frac{18}{15}