How to find the equation of a line?

Question

i need help on my math homework please!! this is the question..

find an equation for the line perpendicular to the line y=1/2x+4 and containing the point (1,-2). Write the solution in slope intercept form.

Answer 1

omg i did this last year.

y=mx+b

y=2x+b

(-3)=2(2)+b

lol sorry.i know the first 2 are right

Answer 2

slop is -2 because it's opposite reciprocal

(-2)=-2(1) + b   -2+2 = b  therefore b=0   y=-2x is your answer