Question: Solve this system of equations by using elimination.
{
2x + 3y = 8
5x + 6y = 17
}
(?, _)
1. **State the problem:** Solve the system of equations using elimination:
$$\begin{cases} 2x + 3y = 8 \\ 5x + 6y = 17 \end{cases}$$
2. **Write down the elimination method formula:** We want to eliminate one variable by making the coefficients of either $x$ or $y$ the same (or opposites) in both equations.
3. **Eliminate $y$:** Multiply the first equation by $2$ to match the coefficient of $y$ in the second equation:
$$2 \times (2x + 3y) = 2 \times 8 \Rightarrow 4x + 6y = 16$$
Now the system is:
$$\begin{cases} 4x + 6y = 16 \\ 5x + 6y = 17 \end{cases}$$
4. **Subtract the second equation from the first:**
$$ (4x + 6y) - (5x + 6y) = 16 - 17 $$
$$ 4x + 6y - 5x - 6y = -1 $$
$$ (4x - 5x) + (6y - 6y) = -1 $$
$$ -x + \cancel{6y} - \cancel{6y} = -1 $$
$$ -x = -1 $$
5. **Solve for $x$:**
$$ x = 1 $$
6. **Substitute $x=1$ into one of the original equations to find $y$:** Use the first equation:
$$ 2(1) + 3y = 8 $$
$$ 2 + 3y = 8 $$
$$ 3y = 8 - 2 $$
$$ 3y = 6 $$
$$ y = \frac{6}{3} $$
$$ y = 2 $$
7. **Final answer:** The solution to the system is
$$ (x, y) = (1, 2) $$