4x^4 - 10x^3 +8x^2 / 2x?

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= (4x⁴ - 10x³ + 8x²)/2x
= 2x³ - 5x² + 4x
= x(2x² - 5x + 4)

Answer: x(2x² - 5x + 4)

Assuming that question should read as :-

( 4 x^4 - 10 x^3 + 8 x^2 ) / 2 x

2 x^3 - 5 x^2 + 4 x

PS
AS GIVEN, question would have to be read as ::-
4 x^4 - 10 x^3 + ( 8 x^2 / 2 x )

4x^4 - 10x^3 +8x^2 / 2x = 2x(2x^3 -5x^2 + 4x) / 2x = 2x^3 -5x^2 + 4x
x mustn't become 0

(4x^4 - 10x^3 + 8x^2)/(2x)
= [2x^2(2x^2 - 5x + 8)]/(2x)
= x(2x^2 - 5x + 8)

4x^4 - 10x^3 +8x^2 / 2x = 2x(2x^3 -5x^2 + 4x) / 2x = 2x^3 -5x^2 + 4x
x mustn't become 0