Questions: Solve this system: x+3 y=4, 2 x-6 y=8.
A. x=4 ; y=0
B. x=0 ; y=4
C. no solution
D. infinitely many solutions
Transcript text: 43. Solve this system: $\begin{array}{l}x+3 y=4 \\ 2 x-6 y=8\end{array}$.
A. $x=4 ; y=0$
B. $x=0 ; y=4$
C. no solútion
D. infinitely many solutions
Solution
Solution Steps
Step 1: Write down the system of equations
The given system of equations is:
\[
\begin{cases}
x + 3y = 4 \quad \text{(1)} \\
2x - 6y = 8 \quad \text{(2)}
\end{cases}
\]
Step 2: Simplify the second equation
Divide equation (2) by 2 to simplify:
\[
\frac{2x - 6y}{2} = \frac{8}{2}
\]
This simplifies to:
\[
x - 3y = 4 \quad \text{(2a)}
\]
Step 3: Add equations (1) and (2a)
Add equation (1) and equation (2a):
\[
(x + 3y) + (x - 3y) = 4 + 4
\]
Simplify:
\[
2x = 8
\]
Solve for \( x \):
\[
x = 4
\]
Step 4: Substitute \( x = 4 \) into equation (1)
Substitute \( x = 4 \) into equation (1):
\[
4 + 3y = 4
\]
Solve for \( y \):
\[
3y = 0 \implies y = 0
\]
Step 5: Verify the solution
Substitute \( x = 4 \) and \( y = 0 \) into equation (2):
\[
2(4) - 6(0) = 8 \implies 8 = 8
\]
The solution satisfies both equations.