Question

What is the value of polynomial 2 x cube minus 2 x when x = 2 - 1?

Answer 1

$x = 2 - 1 = 1 \\ 2x {}^{3} - 2x = 2 \times 1 {}^{3} + 2 \times 1 \\ = 2 \times 1 + 2 = 2 + 2 = 4 \: ans...$

Answer 2

2x^3-2x is polynomial
where x =2 - 1
then
=2(2-1) ^3-2(2-1)
=2(1) ^3-2(1)
=2*1-2*1
=2-2=0