Use the substitution method to solve the system 2.5x + y = -2,3х + 2y = 0.

(1 point)
O (3, -2)
• no solution
O (-2,3)
• infinite solutions

1 answer

To solve the system of equations using the substitution method, we'll start with the given equations:

  1. \( 2.5x + y = -2 \) (Equation 1)
  2. \( 3x + 2y = 0 \) (Equation 2)

Step 1: Solve one of the equations for one variable.

Let's solve Equation 1 for \( y \):

\[ y = -2 - 2.5x \]

Step 2: Substitute this expression for \( y \) into Equation 2.

Now substitute \( y \) in Equation 2:

\[ 3x + 2(-2 - 2.5x) = 0 \]

Distributing the \( 2 \):

\[ 3x - 4 - 5x = 0 \]

Combine like terms:

\[ -2x - 4 = 0 \]

Step 3: Solve for \( x \)

Add \( 4 \) to both sides:

\[ -2x = 4 \]

Divide by \(-2\):

\[ x = -2 \]

Step 4: Substitute \( x \) back to find \( y \)

Now substitute \( x = -2 \) back into the equation we derived for \( y \):

\[ y = -2 - 2.5(-2) \] \[ y = -2 + 5 = 3 \]

Step 5: Solution

So the solution to the system is:

\[ (x, y) = (-2, 3) \]

Thus, the answer is: \(\boxed{(-2, 3)}\).