Step 1 :First, we need to find the slope of the line that is perpendicular to the given line. The slope of a line in standard form, \(Ax + By = C\), is \(-A/B\). So, the slope of the given line is \(-3/7\). The slope of a line perpendicular to this would be the negative reciprocal, which is \(7/3\).
Step 2 :Next, we use the point-slope form of a line, \(y - y_1 = m(x - x_1)\), where \((x_1, y_1)\) is a point on the line and \(m\) is the slope. Substituting the given point \((1,9)\) and the slope \(7/3\), we can find the equation of the line in slope-intercept form.
Step 3 :Finally, we can rearrange this equation into standard form.
Step 4 :\(\boxed{\text{Final Answer:}}\)
Step 5 :a) The equation of the line in slope-intercept form is \(\boxed{y = \frac{7}{3}x + \frac{20}{3}}\).
Step 6 :b) The equation of the line in standard form is \(\boxed{7x - 3y = -20}\).