1. **State the problem:** Solve the system of linear equations using the elimination method.
Given the first system:
$$28.\quad 2x = 11 - y$$
$$\frac{x}{5} + \frac{y}{4} = 1$$
2. **Rewrite equations in standard form:**
From the first equation:
$$2x + y = 11$$
From the second equation multiply both sides by 20 (LCM of 5 and 4):
$$4x + 5y = 20$$
3. **Elimination method:**
Multiply the first equation by 4 to align coefficients of $x$:
$$8x + 4y = 44$$
Now subtract the second equation:
$$8x + 4y = 44$$
$$-(4x + 5y = 20)$$
Gives:
$$4x - y = 24$$
4. **Solve for $y$:**
$$4x - y = 24 \implies y = 4x - 24$$
5. **Substitute $y$ back into one original equation:**
Use $2x + y = 11$:
$$2x + (4x - 24) = 11$$
$$6x - 24 = 11$$
$$6x = 35$$
$$x = \frac{35}{6}$$
6. **Find $y$:**
$$y = 4\times \frac{35}{6} - 24 = \frac{140}{6} - 24 = \frac{140}{6} - \frac{144}{6} = -\frac{4}{6} = -\frac{2}{3}$$
**Final solution:**
$$x = \frac{35}{6}, \quad y = -\frac{2}{3}$$
Linear Elimination A022E7
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