Unravel the System: Solve for x and y in Fractional Equations

Question

Look at the two equations below. Calculate the values of x and y using the substitution method.

{xy2+y+x3=6yx5y+x1=8 \begin{cases}\frac{x-y}{2}+\frac{-y+x}{3}=-6 \\ \frac{-y-x}{5}-\frac{y+x}{1}=8\end{cases}

Video Solution

Step-by-Step Solution

To solve this problem, we'll break it down into clear steps:

  • Step 1: Simplify the given equations for easier manipulation.
  • Step 2: Use the substitution method to express one variable in terms of the other from one equation.
  • Step 3: Insert this expression into the other equation to solve for one variable.
  • Step 4: Finally, substitute back to find the second variable.

Now, let's work through each step:

Step 1: Simplify the first equation.
The first equation is: xy2+y+x3=6 \frac{x-y}{2} + \frac{-y+x}{3} = -6
First, let's find a common denominator of 6 for the fractions: 3(xy)+2(y+x)6=6 \frac{3(x-y) + 2(-y+x)}{6} = -6
This simplifies to: 3x3y2y+2x6=6 \frac{3x-3y-2y+2x}{6} = -6
5x5y6=6 \frac{5x-5y}{6} = -6

Step 1 (cont.): Multiply both sides by 6 to get rid of the denominator:
5x5y=36 5x - 5y = -36
Divide every term by 5 to make it simpler: xy=365 x - y = -\frac{36}{5} x=y365 x = y - \frac{36}{5} (Equation 1)

Step 2: Simplify the second equation.
The second equation is: yx5(y+x)=8 \frac{-y-x}{5} - (y + x) = 8 Multiply through by 5 to clear the fraction from the first term: yx5(y+x)=40 -y-x - 5(y + x) = 40 This expands to: yx5y5x=40 -y-x - 5y - 5x = 40 Combine like terms: 6y6x=40 -6y - 6x = 40 Divide every term by -6 for simplicity: y+x=406 y + x = -\frac{40}{6} y+x=203 y + x = -\frac{20}{3} (Equation 2)

Step 3: Substitute for x x in Equation 2 using Equation 1.
From (Equation 1), x=y365 x = y - \frac{36}{5} . Substitute this into Equation 2: y+(y365)=203 y + (y - \frac{36}{5}) = -\frac{20}{3} This gives: 2y365=203 2y - \frac{36}{5} = -\frac{20}{3} Add 365\frac{36}{5} to both sides to isolate 2y2y: 2y=203+365 2y = -\frac{20}{3} + \frac{36}{5}

Convert both terms to a common denominator to add them together. The common denominator of 3 and 5 is 15: 2y=10015+10815 2y = -\frac{100}{15} + \frac{108}{15} This simplifies to: 2y=815 2y = \frac{8}{15} Divide both sides by 2 to solve for y y : y=4150.266 y = \frac{4}{15} \approx 0.266

Step 4: Solve for x x using y y 's value in Equation 1.
Plug y=415 y = \frac{4}{15} back into Equation 1: x=415365 x = \frac{4}{15} - \frac{36}{5} To add, convert to a common denominator, which can be 15: x=41510815 x = \frac{4}{15} - \frac{108}{15} x=410815 x = \frac{4 - 108}{15} x=104156.933 x = -\frac{104}{15} \approx -6.933

Therefore, after solving both variables, the values that satisfy the given system of equations are:
x6.933, y0.266 x \approx -6.933,\ y \approx 0.266 .

Answer

x=6.933,y=0.266 x=-6.933,y=0.266