Question

1) 3 (5x - 2y + 5z ) - 5 (4x - 3y - 2z ) - 6 (2x - 4y+ 6z)=
2) 6 (-x2 - 3x + 5) -7 (2x2 -4x +6) +5 (5x2  +2x - 1 )=
3)(x+4) x(2x - 5) +( 2x+3)x(x+1)-4x (x+2)
4) (x+2)-(x2-x+3)-(x+1)x (x2 +2x -5)=

Va rog tare mult sa ma ajutati.... 

Answer 1

1) 3 (5x - 2y + 5z ) - 5 (4x - 3y - 2z ) - 6 (2x - 4y+ 6z)=
=15x - 6y + 15z  - 20x + 15y +10z  - 12x +24y -36z=
=-17x +33y -11z

2) 6 (-x² - 3x + 5) -7 (2x² -4x +6) +5 (5x² +2x - 1 )=
= -6x² - 18x + 30 -14x²+28x -42 +25x² +10x - 5=
= 5x² +20x -17 

3) (x+4) x(2x - 5) +( 2x+3)(x+1)-4 (x+2)=
= 2x²+8x-5x-20 + 2x²+3x+2x+3-4x-8=
= 4x²+4x-25

4) (x+2)-(x2-x+3)-(x+1) (x² +2x -5)=
= x+2-x²+x-3-  x³-x²-2x²-2x+5x+5=
=- x³ -4x²+5x+4