Answer :
Let's solve the system of linear equations:
[tex]\[ \left\{ \begin{array}{l} 2x - 3y = -15 \\ 8x - 4y = -1 \end{array} \right. \][/tex]
First, we label the equations for reference:
[tex]\[ \begin{array}{c} \text{(1)} \quad 2x - 3y = -15 \\ \text{(2)} \quad 8x - 4y = -1 \end{array} \][/tex]
### Step 1: Normalize equation (2)
To make equation [tex]\((2)\)[/tex] simpler, let's divide it by [tex]\(4\)[/tex], simplifying it:
[tex]\[ \frac{8x - 4y = -1}{4} \quad \Rightarrow \quad 2x - y = -\frac{1}{4} \][/tex]
Now we have the system:
[tex]\[ \left\{ \begin{array}{l} 2x - 3y = -15 \\ 2x - y = -\frac{1}{4} \end{array} \right. \][/tex]
### Step 2: Eliminate [tex]\(x\)[/tex]
Next, we eliminate [tex]\(x\)[/tex] by subtracting the second equation from the first. Let's rewrite the equations:
[tex]\[ \text{(1)} \quad 2x - 3y = -15 \][/tex]
[tex]\[ \text{(3)} \quad 2x - y = -\frac{1}{4} \][/tex]
Now subtract equation (3) from equation (1):
[tex]\[ (2x - 3y) - (2x - y) = -15 - \left(-\frac{1}{4}\right) \][/tex]
Simplify:
[tex]\[ 2x - 3y - 2x + y = -15 + \frac{1}{4} \][/tex]
[tex]\[ -2y = -15 + \frac{1}{4} \][/tex]
Convert [tex]\(-15\)[/tex] to a fraction with the same denominator:
[tex]\[ -15 = -\frac{60}{4} \][/tex]
Now:
[tex]\[ -2y = -\frac{60}{4} + \frac{1}{4} \][/tex]
Combine the fractions:
[tex]\[ -2y = -\frac{59}{4} \][/tex]
Divide both sides by [tex]\(-2\)[/tex]:
[tex]\[ y = \frac{\frac{59}{4}}{2} = \frac{59}{8} \][/tex]
### Step 3: Solve for [tex]\(x\)[/tex]
Now that we have [tex]\(y = \frac{59}{8}\)[/tex], substitute this value back into equation (3):
[tex]\[ 2x - y = -\frac{1}{4} \][/tex]
Substitute [tex]\(y\)[/tex]:
[tex]\[ 2x - \frac{59}{8} = -\frac{1}{4} \][/tex]
Convert [tex]\(-\frac{1}{4}\)[/tex] to a fraction with the same denominator:
[tex]\[ -\frac{1}{4} = -\frac{2}{8} \][/tex]
So the equation becomes:
[tex]\[ 2x - \frac{59}{8} = -\frac{2}{8} \][/tex]
Add [tex]\(\frac{59}{8}\)[/tex] to both sides:
[tex]\[ 2x = \frac{59}{8} - \frac{2}{8} = \frac{57}{8} \][/tex]
Divide both sides by 2:
[tex]\[ x = \frac{\frac{57}{8}}{2} = \frac{57}{16} \][/tex]
### Final Answer
Thus, the solution to the system of equations is:
[tex]\[ x = \frac{57}{16}, \quad y = \frac{59}{8} \][/tex]
[tex]\[ \left\{ \begin{array}{l} 2x - 3y = -15 \\ 8x - 4y = -1 \end{array} \right. \][/tex]
First, we label the equations for reference:
[tex]\[ \begin{array}{c} \text{(1)} \quad 2x - 3y = -15 \\ \text{(2)} \quad 8x - 4y = -1 \end{array} \][/tex]
### Step 1: Normalize equation (2)
To make equation [tex]\((2)\)[/tex] simpler, let's divide it by [tex]\(4\)[/tex], simplifying it:
[tex]\[ \frac{8x - 4y = -1}{4} \quad \Rightarrow \quad 2x - y = -\frac{1}{4} \][/tex]
Now we have the system:
[tex]\[ \left\{ \begin{array}{l} 2x - 3y = -15 \\ 2x - y = -\frac{1}{4} \end{array} \right. \][/tex]
### Step 2: Eliminate [tex]\(x\)[/tex]
Next, we eliminate [tex]\(x\)[/tex] by subtracting the second equation from the first. Let's rewrite the equations:
[tex]\[ \text{(1)} \quad 2x - 3y = -15 \][/tex]
[tex]\[ \text{(3)} \quad 2x - y = -\frac{1}{4} \][/tex]
Now subtract equation (3) from equation (1):
[tex]\[ (2x - 3y) - (2x - y) = -15 - \left(-\frac{1}{4}\right) \][/tex]
Simplify:
[tex]\[ 2x - 3y - 2x + y = -15 + \frac{1}{4} \][/tex]
[tex]\[ -2y = -15 + \frac{1}{4} \][/tex]
Convert [tex]\(-15\)[/tex] to a fraction with the same denominator:
[tex]\[ -15 = -\frac{60}{4} \][/tex]
Now:
[tex]\[ -2y = -\frac{60}{4} + \frac{1}{4} \][/tex]
Combine the fractions:
[tex]\[ -2y = -\frac{59}{4} \][/tex]
Divide both sides by [tex]\(-2\)[/tex]:
[tex]\[ y = \frac{\frac{59}{4}}{2} = \frac{59}{8} \][/tex]
### Step 3: Solve for [tex]\(x\)[/tex]
Now that we have [tex]\(y = \frac{59}{8}\)[/tex], substitute this value back into equation (3):
[tex]\[ 2x - y = -\frac{1}{4} \][/tex]
Substitute [tex]\(y\)[/tex]:
[tex]\[ 2x - \frac{59}{8} = -\frac{1}{4} \][/tex]
Convert [tex]\(-\frac{1}{4}\)[/tex] to a fraction with the same denominator:
[tex]\[ -\frac{1}{4} = -\frac{2}{8} \][/tex]
So the equation becomes:
[tex]\[ 2x - \frac{59}{8} = -\frac{2}{8} \][/tex]
Add [tex]\(\frac{59}{8}\)[/tex] to both sides:
[tex]\[ 2x = \frac{59}{8} - \frac{2}{8} = \frac{57}{8} \][/tex]
Divide both sides by 2:
[tex]\[ x = \frac{\frac{57}{8}}{2} = \frac{57}{16} \][/tex]
### Final Answer
Thus, the solution to the system of equations is:
[tex]\[ x = \frac{57}{16}, \quad y = \frac{59}{8} \][/tex]