👤

Descomputeti in factori a) 25xla puterea 2-81
b) 4xla puterea 3 -x


Răspuns :

a) 25x²-81 = (5x)² -9² = (5x+9)(5x-9)
b) 4x³ -x = x(4x² -1 ) = x(2x+1)(2x-1)
25x²-81=(5x+9)(5x-9)
4x³-x=x(4x²-1)=x(2x+1)(2x-1)