Find the value of x if`|(1,4,20),(1,-2,-5),(1,2x,5x^2)|=0`

Without expanding, the determinant, find the two values of x, satisfying. |(1,4,20),(1,-2,5),(1,2x,5x^2)|=0

Find the value of x if. |(x,-1,2),(2x,1,-3),(3,-4,5)|=29

Find the value of x if |(1,2x,4x),(1,4,16),(1,1,1)|=0