1. **State the problem:** Solve the system of equations by substitution:
$$\begin{cases} y = 5x + 7 \\ y = 4x - 3 \end{cases}$$
2. **Use substitution:** Since both expressions equal $y$, set them equal to each other:
$$5x + 7 = 4x - 3$$
3. **Solve for $x$:**
$$5x + 7 = 4x - 3$$
Subtract $4x$ from both sides:
$$5x - \cancel{4x} + 7 = \cancel{4x} - 3$$
$$x + 7 = -3$$
Subtract 7 from both sides:
$$x + \cancel{7} = -3 - \cancel{7}$$
$$x = -10$$
4. **Find $y$ by substituting $x = -10$ into one of the original equations:**
Using $y = 5x + 7$:
$$y = 5(-10) + 7 = -50 + 7 = -43$$
5. **Solution:**
$$(x, y) = (-10, -43)$$
This is the point where the two lines intersect.
Substitution System E1D9D5
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