Solve the Fraction Equation: Finding X in (6-x)/7 = 3(x-8)/9

Question

Solve for X:

6x7=(x8)×39 \frac{6-x}{7}=\frac{(x-8)\times3}{9}

Video Solution

Solution Steps

00:00 Find X
00:03 Multiply by the common denominator to eliminate fractions
00:22 Simplify as much as possible
00:25 Make sure to open brackets properly, multiply by each factor
01:02 Arrange the equation so that one side has only the unknown X
01:12 Collect like terms
01:18 Isolate X
01:25 And this is the solution to the question

Step-by-Step Solution

Let's solve the equation 6x7=(x8)×39\frac{6-x}{7} = \frac{(x-8)\times3}{9} step by step:

  • Step 1: Cross-multiply to eliminate the fractions:
  • We have:

    (6x)×9=((x8)×3)×7(6-x) \times 9 = ((x-8) \times 3) \times 7

  • Step 2: Expand both sides:
  • Expanding both products gives:

    9(6x)=73(x8)9(6-x) = 7 \cdot 3(x-8)

    This simplifies to:

    549x=21(x8)54 - 9x = 21(x-8)

  • Step 3: Expand the right side and simplify:
  • Expanding the right side gives:

    549x=21x16854 - 9x = 21x - 168

  • Step 4: Rearrange terms to solve for x x :
  • Bring the terms involving x x to one side by adding 9x 9x to both sides:

    54=30x16854 = 30x - 168

    Add 168 to both sides to isolate terms involving x x :

    222=30x222 = 30x

  • Step 5: Solve for x x :
  • Divide both sides by 30 to find x x :

    x=22230=7.4x = \frac{222}{30} = 7.4

Therefore, the solution to the equation is x=7.4 x = 7.4 .

Answer

7.4 7.4