Question

Ajutatima va exerciti 11(b,c),12,12,13,14 va rog mult 

Answer 1

12)a)=36x²+18x+18x+9-(25x-20x-20x+16)=
=36x²+36x+9-25x+40x-16=
=36x²+51x-7

b)(x-5)³=x³-3x²·5+3x·25-125=x³-15x²+75x-125
8x³-(x-5)³=8x³-x³+15x²-75x+125=
=7x³+15x²-75x+125

c)(x+1)³=x³+3x²+3x+1
125x³+(x+1)³=125x³+x³+3x²+3x+1=
=126x³+3x²+3x+1

13)a)=x³+2x³-2x²-8=3x³-2x²-8

b) notam x³=t
t²-4t+4=(t-2)(t-2)
x⁶-4x³+4=(x³-2)(x³-2)=(x³-2)²

d)=x²(x²-1)+2(x+1)