Question

Efectuaţi, folosind formulele de calcul prescurtat:
a) (5x + 7)(5x-7)-(4x - 3)²-(3x + 2)² - 3(4x-8); b) (√15x+1)-(3x+2)²-(√6x+3)+4(3x+5);
c) (3x - 2)²-(2x + 5)(2x-5)-5(x + 1)²;
d) (2x + 5)²(x+3)(x-2)-3(x + 2)²
e) 2(x+5)(x-1)-(x + 2)²-(x+5)(x - 5);
f) (3x + 4)² - 6(x + 2)(x + 4) - 3(x + 4)(x − 4).​

Answer 1

a) 25x²-49 - (16x²-24x+9) - (9x²+12x+4) - 12x+24 =

25x²-12x-25 - 16x²+24x-9 - 9x²-12x-4 = 38

b) V15x+1 - (9x²+12x+4) - V6x-3 + 12x+20 =

V15x-V6x+12x+18 - 9x²-12x-4 =

-9x²+V15x-V6x+12x+14

c) 9x²-12x+4 - (4x²-25) - 5(x²+2x+1) =

9x²-12x+4-4x²+25-5x²-10x-5 =

-22x+24

d) (4x²+20x+25)(x²-2x+3x-6) - 3(x²+4x+4) =

4x⁴+4x³-24x²+20x³+20x²-120x+25x²+25x-150 - 3x²-12x-12 =

4x⁴+24x³+18x²-107x-162

e) (2x+10)(x-1) - (x²+4x+4) - (x²-25) =

2x²-2x+10x-10-x²-4x-4-x²+25 =

4x+11

f) 9x²+24x+16 - 6(x²+6x+8) - 3(x²-16) =

9x²+24x+16-6x²-36x-48-3x²+48 =

-12x+16

De asemenea ai in atasament formulele si ca ai scris bine cerintele, altfel rezolvarile nu sunt bune :)