To solve the system of equations given by:
- \( 2y - 8x = 16 \)
- \( 9x + 4y = 11 \)
we can use either the substitution method or the elimination method. Here, we’ll use the elimination method.
First, let's rewrite the equations in standard form:
- \( -8x + 2y = 16 \)
- \( 9x + 4y = 11 \)
Next, we can multiply the entire first equation by 2 to align the \(y\) coefficients:
- \( -16x + 4y = 32 \)
- \( 9x + 4y = 11 \)
Now we can subtract the second equation from the first to eliminate \(y\):
\[ (-16x + 4y) - (9x + 4y) = 32 - 11 \]
This simplifies to:
\[ -16x - 9x + 4y - 4y = 21 \]
\[ -25x = 21 \]
Now, divide both sides by -25:
\[ x = -\frac{21}{25} \]
Now, substitute the value of \(x\) back into one of the original equations to find \(y\). We can substitute it into the first equation:
\[ 2y - 8(-\frac{21}{25}) = 16 \]
This simplifies to:
\[ 2y + \frac{168}{25} = 16 \]
Now, convert 16 into a fraction with the same denominator:
\[ 2y + \frac{168}{25} = \frac{400}{25} \]
Subtract \(\frac{168}{25}\) from both sides:
\[ 2y = \frac{400}{25} - \frac{168}{25} \]
\[ 2y = \frac{232}{25} \]
Now, divide both sides by 2:
\[ y = \frac{116}{25} \]
So the solution to the system of equations is:
\[ x = -\frac{21}{25}, \quad y = \frac{116}{25} \]
Thus, the solution is:
\[ \left(x, y\right) = \left(-\frac{21}{25}, \frac{116}{25}\right) \]