1. **State the problem:** Solve the system of linear equations:
$$3x - y = 4$$
$$7x + 2y = 18$$
2. **Choose a method:** We will use the substitution or elimination method. Here, elimination is convenient.
3. **Make coefficients of $y$ equal:** Multiply the first equation by 2 to align the $y$ terms:
$$2(3x - y) = 2(4) \Rightarrow 6x - 2y = 8$$
4. **Write the new system:**
$$6x - 2y = 8$$
$$7x + 2y = 18$$
5. **Add the two equations to eliminate $y$:**
$$ (6x - 2y) + (7x + 2y) = 8 + 18 $$
$$ 6x + 7x + (-2y + 2y) = 26 $$
$$ 13x + 0 = 26 $$
$$ 13x = 26 $$
6. **Solve for $x$:**
$$ x = \frac{26}{13} $$
$$ x = 2 $$
7. **Substitute $x=2$ into the first original equation to find $y$:**
$$ 3(2) - y = 4 $$
$$ 6 - y = 4 $$
8. **Solve for $y$:**
$$ -y = 4 - 6 $$
$$ -y = -2 $$
$$ y = 2 $$
9. **Final solution:**
$$ (x, y) = (2, 2) $$
This means the two lines intersect at the point $(2, 2)$, which is the solution to the system.
Linear System A9B435
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.