Linear System C2C883
1. **State the problem:** Solve the system of linear equations:
$$4x + y = 7$$
$$5x + 3y = 7$$
2. **Formula and method:** We can use the substitution or elimination method. Here, we'll use elimination.
3. **Elimination method:** Multiply the first equation by 3 to align the coefficients of $y$:
$$3(4x + y) = 3(7) \Rightarrow 12x + 3y = 21$$
4. **Subtract the second equation from this new equation:**
$$ (12x + 3y) - (5x + 3y) = 21 - 7 $$
$$ 12x - 5x + 3y - 3y = 14 $$
$$ 7x = 14 $$
5. **Solve for $x$:**
$$ x = \frac{14}{7} = 2 $$
6. **Substitute $x=2$ into the first original equation to find $y$:**
$$ 4(2) + y = 7 $$
$$ 8 + y = 7 $$
$$ y = 7 - 8 = -1 $$
7. **Final answer:**
$$ x = 2, \quad y = -1 $$