Answer
given equation,
x⁵²-21 x+20
A number to be divisible by the another number means that on dividing the remainder should be zero.
if x⁵²-21 x+20 is divisible by x− 1 means that x-1 should completely divide the equation.
so,
x -1 = 0
x = 1
x⁵²-21 x+20 to be divisible it should be equal to zero when x = 1
putting x = 1
= (1)⁵²-21 (1)+20
= 1 - 21 + 20
= 21 -21
= 0
hence x = 1 is the root of the equation
so, x⁵²-21 x+20 is divisible by x− 1.
