find the excluded values :
f / gx x = 2 x ( -3 ) , g = 0
multiply both sides :
fx = 6g
divide both sides :
x = -6g / f , f = 0
rewrite the fraction :
x = - 6g / f , f = 0
write the restrictions :
x = -6g / f , f = 0 , g. = 0
Answer :
x = -6g / f , f = 0 , g. = 0