Use elimination to find the solution to the system of equations.

[tex]\[
\begin{array}{r}
4x + y = 8 \\
3x - 2y = 6
\end{array}
\][/tex]

A. [tex]\(x = -3, y = 20\)[/tex]
B. [tex]\(x = 6, y = 6\)[/tex]
C. [tex]\(x = 6, y = -16\)[/tex]
D. [tex]\(x = 2, y = 0\)[/tex]



Answer :

To solve the system of equations using the elimination method, we must eliminate one of the variables to find the values of [tex]\(x\)[/tex] and [tex]\(y\)[/tex]. Let's follow these steps:

The given system of equations is:
[tex]\[ \begin{array}{r} 4x + y = 8 \quad \text{(1)} \\ 3x - 2y = 6 \quad \text{(2)} \end{array} \][/tex]

Step 1: Make the coefficients of [tex]\( y \)[/tex] the same

To eliminate [tex]\( y \)[/tex], we need to make the coefficients of [tex]\( y \)[/tex] in both equations equal. The least common multiple of the coefficients [tex]\(1\)[/tex] and [tex]\(-2\)[/tex] is [tex]\(2\)[/tex]. Thus, we will multiply equation (1) by 2 to make the coefficient of [tex]\( y \)[/tex] equal to 2 in absolute value.

[tex]\[ 2 \times (4x + y) = 2 \times 8 \][/tex]
[tex]\[ 8x + 2y = 16 \quad \text{(3)} \][/tex]

Now the system of equations looks like this:
[tex]\[ \begin{array}{r} 8x + 2y = 16 \quad \text{(3)} \\ 3x - 2y = 6 \quad \text{(2)} \end{array} \][/tex]

Step 2: Add the equations

Next, add equations (3) and (2) together to eliminate [tex]\( y \)[/tex].

[tex]\[ (8x + 2y) + (3x - 2y) = 16 + 6 \][/tex]
The [tex]\( 2y \)[/tex] and [tex]\( -2y \)[/tex] cancel out each other:
[tex]\[ 8x + 3x = 22 \][/tex]
[tex]\[ 11x = 22 \][/tex]

Step 3: Solve for [tex]\( x \)[/tex]

Divide both sides by 11:
[tex]\[ x = \frac{22}{11} \][/tex]
[tex]\[ x = 2 \][/tex]

Step 4: Substitute [tex]\( x \)[/tex] back to find [tex]\( y \)[/tex]

Now substitute [tex]\( x = 2 \)[/tex] back into one of the original equations to find [tex]\( y \)[/tex]. We will use equation (1):

[tex]\[ 4x + y = 8 \][/tex]
Substitute [tex]\( x = 2 \)[/tex]:
[tex]\[ 4(2) + y = 8 \][/tex]
[tex]\[ 8 + y = 8 \][/tex]
Subtract 8 from both sides:
[tex]\[ y = 0 \][/tex]

Step 5: Verify the solution

We have found [tex]\( x = 2 \)[/tex] and [tex]\( y = 0 \)[/tex]. We should verify these values in the second equation to ensure they satisfy the original system.

Substitute [tex]\( x = 2 \)[/tex] and [tex]\( y = 0 \)[/tex] into equation (2):
[tex]\[ 3(2) - 2(0) = 6 \][/tex]
[tex]\[ 6 = 6 \][/tex]

Since both equations are satisfied, the solution to the system of equations is:
[tex]\[ x = 2, \quad y = 0 \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{D. \, x = 2, \, y = 0} \][/tex]