To solve the equations you provided, we start with the first equation:
\[ -2x = 7y - 13 \]
Given that \( x = 3 \), we can substitute \( x \) into the equation:
\[ -2(3) = 7y - 13 \]
This simplifies to:
\[ -6 = 7y - 13 \]
Now, add 13 to both sides to isolate the term with \( y \):
\[ -6 + 13 = 7y \]
\[ 7 = 7y \]
Now, divide both sides by 7 to solve for \( y \):
\[ y = 1 \]
Now, regarding the second part of your statement, it appears you were trying to express the equation in slope-intercept form \( y = mx + b \). Let's derive that from the original equation:
Starting from:
\[ -2x = 7y - 13 \]
We arrange it to solve for \( y \):
\[ 7y = -2x + 13 \]
Now, divide every term by 7:
\[ y = -\frac{2}{7}x + \frac{13}{7} \]
So you are correct; the equation can indeed be expressed as:
\[ y = -\frac{2}{7}x + \frac{13}{7} \]
And we also found \( y = 1 \) when \( x = 3 \).