a). (3x-1)² = 9x²-6x+1 ;
9x²- 6x+1 - 20x -24 = 9x²- 9x+9 + 2 ordonam,apoi restrangem termenii asemenea ...
-9x²-9x²-6x-20x+9x = 2 +24 -1
-17x = 25
x = - 25 / 17
b). 1/2 - 5x/2 + 4x² -16 - 3/5 = 5/4 - 5x/8 +4x²- 3x | *40
20 -100x + 160x²- 640 -24 = 50 - 25x +160x² -120x
-100x+25x+120x = 50 - 20 +640+24
45x = 694
x = ....