Question

Rút gọn a, (x-1) (x²+x²+x+1) b, (x+1) (x^4 -x³+x²-x+1)

Answer 1

 a,(x-1) (x²+x²+x+1)

=(x-1)(2x²+x+1)

=2x³+2x+x-2x²-x-1

=2x³-2x²+2x-1

b, (x+1) (x⁴ -x³+x²-x+1)

=x⁵-x⁴+x³-x²+x+x⁴-x³+x²-x+1

=x⁵+1