Question

Va rog!
Rezolvati ecuatiile:
1) (x-1)²-2(x+3)=(x+2)²-17x
2) (x+5)(x-5)-(x-3)²=x-9
4) (x-3)(x+3)+(x+1)=2(x-5)²+3x-1
5) (3x+1)²-(2x-1)²=5(-x+4)²+4(2x+1)

Answer 1

1) x²-2x+1-2x-6=x²+4x+4-17x
    x²-x²-4x-4x+17x=4-1+6
    -8x+17x=9
       9x=9
       x=9/9
       x=1
2)x²-25-x²+6x-9=x-9
   6x-x=-9+9+25
       5x=25
        x=25/5
        x=5
4)x²-9+x+1=2(x²-10+25)+3x-1
   x²+x-8=2x²-20x+50+3x-1
   x²-2x²+x+20x-3x=-1+50+8
   -x²+18x= 57
   -x²+18x-57=0
   faci si tu delta , altfel daca nu da x-ul ceva e gresit din exercitiu . calculele sunt corecte.
5)9x²+6x+1-4x²+4x-1=5(x²-8x+16)+8x+4
    5x²+10x=5x²-40x+80+8x+4
    42x=84
    x=84/42
    x=2