Question

Write an equation of the line that passes through (0,9) and is perpendicular to the line

y = -x + 1

Answer 1

y=x+9

y=mx+c

where m is gradient, c is the intercept

for perpendicular line m1/m2=-1

m1=m2*(-1)

m1=-1*-1=1

y-9/x-0=1

y=x+9

Answer 2

slope of y = -x + 1 is -1

so the slope of desired line = -(-1) = 1

equation of the line:

`(y-9)/(x-0) =1\\y-9=x\\y=x+9`