Question

1) Calculand:3(-2a+3b-4c)-2(-4a+5b-7c)-(3a-2b+c)rezultatul este?
2) Reducand termenii asemenea din 3(x²-4x-3)-2(x²-5x-4)-(3x²+4x-3)=?
3) (3x+4)(2x-5)-(x+3)(x-6)-(x+2)(x-1)=?
4) (5x-3)²-(4x-2)²=?
5) 16(3x+2)²-9(x+1)²=?

Answer 1

1) -6a+9b-12c-8a-10b+14c-3a+2b-c= -17a +b+c
2) 3(x²-4x-3)-2(x²-5x-4)-(3x²+4x-3)= 3x²-12x-9-2x²+10x+8-3x²-4x+3= -2x²-6x+2=             = -2(x²+3-1)
3)(3x+4)(2x-5)-(x+3)(x-6)-(x+2)(x-1)= 6x²-15x+8x-20-(x²-6x-3x+18)-(x²-x+2x-2)
=  6x²-15x+8x-20-x²+6x+3x-18-x²+x²+2x-2= 5x² +4x-40= 5x²+4(x-10)

4)(5x-3)²-(4x-2)²= 25x²-30x+9-16x²+16x-4= 9x² -14x +5 

5)16(3x+2)²-9(x+1)²= 16(9x²+12x+4)-9(x²+2x+1)= 144x²+192x+64-9x²-18x-9
            = 135x² +174x+55