Square root of 45 is 6.708… then the square root of 18 is 4.242… so 11?
For the equation of the line expressed as Ax + By + C = 0, the value of the slope (m) is calculated by -A / B. For perpendicular lines, the slope of one should be the negative reciprocal of the other. From the choices given, the lines that are perpendicular is Option A.
If it's a whole number it would be 1 and of it wasn't it's .1 or .09