Algebra · real student question

Solve for x: (2/5)x + 1014 + 4/5 = (5/9)x + 1019 + 4/9.

Question

Solve for xx:

25x+1014+45=59x+1019+49.\frac{2}{5}x+1014+\frac45=\frac{5}{9}x+1019+\frac49.

Step-by-step solution

  1. Combine the constants on each side. Each side has a whole number plus a proper fraction, which merge into mixed numbers:

    1014+45=101445=50745,1019+49=101949=91759.1014+\frac45=1014\tfrac45=\frac{5074}{5},\qquad 1019+\frac49=1019\tfrac49=\frac{9175}{9}.

    Converting straight to improper fractions now means the rest of the problem is pure fraction arithmetic with no mixed-number bookkeeping.

  2. Gather the xx terms on one side and the constants on the other. Subtracting 25x\tfrac25x and 91759\tfrac{9175}{9} from both sides:

    5074591759=(5925)x.\frac{5074}{5}-\frac{9175}{9}=\left(\frac59-\frac25\right)x.

    Moving the smaller coefficient 25\tfrac25 keeps the xx coefficient positive, avoiding a sign flip later.

  3. Compute the coefficient of xx. Over the common denominator 4545:

    5925=25451845=745.\frac59-\frac25=\frac{25}{45}-\frac{18}{45}=\frac{7}{45}.

    The denominators 55 and 99 are coprime, so 4545 is the least common denominator for the whole problem — the same 4545 will reappear on the left.

  4. Compute the constant difference. Again over 4545:

    5074591759=507499175545=456664587545=20945.\frac{5074}{5}-\frac{9175}{9}=\frac{5074\cdot9-9175\cdot5}{45}=\frac{45666-45875}{45}=\frac{-209}{45}.

    Both 4566645666 and 4587545875 are worth checking: 5074×9=456665074\times9=45666 and 9175×5=458759175\times5=45875.

  5. Solve and check exactly. The equation is now 20945=745x\frac{-209}{45}=\frac{7}{45}x, and multiplying both sides by 4545 makes the denominators vanish:

    209=7x    x=209729.857.-209=7x\;\Longrightarrow\;x=-\frac{209}{7}\approx-29.857.

    Since 209=11×19209=11\times19 this does not reduce. Substituting back with exact fractions: both sides evaluate to 70207\frac{7020}{7} ✓.

Answer

x=209729.857x=-\frac{209}{7}\approx-29.857

Need to solve a different problem like this? Open the solver →