the equation of a line which is perpendicular to Y = 1/2X - 5 and goes through the point (0,0)

Answer 1

slope of original line = 1/2
so slope of our line = -1 /(1/2) = -2
so
y = -2 x + b
0 = - 2(0) + b
b = 0
so
y = -2 x