Answer:
it is 1/2
Explanation:
The product of a lines slope M and the slope K of a perpendicular is -1:
M*K=-1
This implies
K=-1/M
since
M * -1/M=-1
In our example we are given a line of slope M=-2 therefore the slope K of a line to perpendicular to this line is:
M*K=-1
-2*K=-1
K=-1/-2=1/2