Solve for X and Y Using Substitution: System of Equations with x + y = 5 and 2x - 3y = -15

Question

Find the value of x and and band the substitution method.

{x+y=52x3y=15 \begin{cases} x+y=5 \\ 2x-3y=-15 \end{cases}

Video Solution

Step-by-Step Solution

To solve this system using the substitution method, we'll follow these steps:

  • Step 1: Solve the first equation for one variable.

  • Step 2: Substitute this expression into the second equation.

  • Step 3: Solve for the second variable.

  • Step 4: Use the value of the second variable to find the first variable.

Step 1: Solve the first equation x+y=5x + y = 5 for yy.
We have: y=5xy = 5 - x.

Step 2: Substitute y=5xy = 5 - x into the second equation 2x3y=152x - 3y = -15.
This gives us: 2x3(5x)=152x - 3(5 - x) = -15.

Step 3: Simplify and solve for x x :
2x15+3xamp;=155x15amp;=155xamp;=0xamp;=0. \begin{aligned} 2x - 15 + 3x &= -15 \\ 5x - 15 &= -15 \\ 5x &= 0 \\ x &= 0. \end{aligned}

Step 4: Substitute x=0x = 0 back into y=5xy = 5 - x to find yy.
yamp;=50yamp;=5. \begin{aligned} y &= 5 - 0 \\ y &= 5. \end{aligned}

Thus, the solution to the system of equations is x=0x = 0 and y=5y = 5.

The correct answer from the list of choices is: x=0,y=5x = 0, y = 5

Answer

x=0,y=5 x=0,y=5