How do you write the equation of the line that passes through the point (1,4) and is parallel to the line 4x+5y=21?
Here's the quick and easy way...
Every line parallel to that one has the same slope.
The slope is determined by the ratio of the coefficients of x and y.
If we keep the left side the same, we'll have a parallel line.
what to put on the right?
Therefore, the line
is parallel to the original and passes through (1, 4).