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

Responses:

(−2,3)

infinite solutions

no solution

(3,−2)

1 answer

To solve the system of equations using the substitution method, we will start with the two equations:

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

First, we can solve Equation 1 for \( y \):

\[ y = -2 - 2.5x \]

Now that we have \( y \) in terms of \( x \), we can substitute this expression for \( y \) into Equation 2:

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

Now simplify:

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

Combine like terms:

\[ -2x - 4 = 0 \]

Now, solve for \( x \):

\[ -2x = 4 \]

\[ x = -2 \]

Now that we have \( x \), we can substitute it back into the expression we found earlier for \( y \):

\[ y = -2 - 2.5(-2) \]

Calculate \( y \):

\[ y = -2 + 5 = 3 \]

Thus, the solution to the system of equations is:

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

So the correct response is:

(−2, 3)