Answer :

Sure! Let's solve this system of linear equations step-by-step.

We have the following system of equations:

[tex]\[ \begin{array}{l} 2x + y = 9 \quad \text{(Equation 1)} \\ x - y = 3 \quad \text{(Equation 2)} \end{array} \][/tex]

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

Let's solve Equation 2 for [tex]\( x \)[/tex].

[tex]\[ x - y = 3 \implies x = y + 3 \][/tex]

Step 2: Substitute the expression found into the other equation.

Substitute [tex]\( x = y + 3 \)[/tex] into Equation 1:

[tex]\[ 2(y + 3) + y = 9 \][/tex]

Step 3: Simplify and solve for [tex]\( y \)[/tex].

Distribute and combine like terms:

[tex]\[ 2y + 6 + y = 9 \][/tex]

[tex]\[ 3y + 6 = 9 \][/tex]

Subtract 6 from both sides:

[tex]\[ 3y = 3 \][/tex]

Divide both sides by 3:

[tex]\[ y = 1 \][/tex]

Step 4: Substitute [tex]\( y \)[/tex] back into the expression found for [tex]\( x \)[/tex].

We have [tex]\( y = 1 \)[/tex] and we previously established [tex]\( x = y + 3 \)[/tex].

[tex]\[ x = 1 + 3 \][/tex]

[tex]\[ x = 4 \][/tex]

Step 5: Write the solution as an ordered pair.

The solution to the system of equations is:

[tex]\[ (x, y) = (4, 1) \][/tex]

Step 6: Verification.

To ensure our solution is correct, let's substitute [tex]\( x = 4 \)[/tex] and [tex]\( y = 1 \)[/tex] back into the original equations:

1. [tex]\( 2x + y = 9 \)[/tex]:
[tex]\[ 2(4) + 1 = 8 + 1 = 9 \][/tex]

2. [tex]\( x - y = 3 \)[/tex]:
[tex]\[ 4 - 1 = 3 \][/tex]

Since both equations are satisfied, the solution [tex]\( (x, y) = (4, 1) \)[/tex] is correct.