Confusing perpendicular questions

Question

The equation of the line that passes through the point (x,y) and is perpendicular to the line having the equation 2x-9y=C can be written in slope formula y=mx+b. Compute m and b in terms of x, y , and c.

 

 

 The equation of the line that passes through the point (0,-9) and is perpendicular to the line having the equation Ax+By=C can be written in slope-intercept form as y=mx+b. Compute m and b in terms of A,B, and C

Answer 1

2x-9y=C

in point slope form that's

y= 2x/9 - C/9 with slope = 2/9 and y-intercept = - C/9

If it passes through (0, -9) plug those numbers into the equation above

to get

-9 = C/9

C= -81

m=2/9

b = - -81/9 = 9