Question

2. Calculaţi, respectând ordinea efectuării operaţiilor:
a) (4x+3)(2x - 5)-(2x-3)(3x + 7);
b) (x-2)(x²-3x+4)-(2-x²)(2-3x) + (x+3)(4x - 3);
c) (3x + 1)[(36x4 - 48x³): (+12x³) -2(x - 1)]- 3x²

Va rog mult dau 100 puncte

Answer 1

Răspuns:

Explicație pas cu pas:

a) (4x+3)(2x - 5)-(2x-3)(3x + 7) =

= 8x²-20x+6x-15 - (6x²+14x-9x-21) =

= 8x²-14x-15 - 6x²-14x+9x+21 =

= 8x²-6x²-14x-14x+9x-15-21 =

= 2x²-17x-36

b) (x-2)(x²-3x+4)-(2-x²)(2-3x) + (x+3)(4x - 3) =

= x³-3x²+4x-2x²+6x-8 - (4-6x-2x²+3x³) + 4x²-3x+12x-9 =

= x³-3x³-3x²-2x²+2x²+4x²+4x+6x+6x-3x+12x-8-4-9 =

= -2x³+x²+25x-21

c) (3x + 1)·[(36x⁴ - 48x³): (+12x³) -2(x - 1)]- 3x² =

= (3x + 1)·[(3x-4)-2x+2] - 3x² = (3x+1)·(x-2) - 3x² =

= 3x²-6x+x-2-3x² = 3x²-3x²-6x+x-2 = -5x-2