Răspuns :
25x²+4=(5x+2)²-20x
4x²+1=(2x+1)²-4x
9x²+25=(3x+5)²-30x
4x²+25=(2x+5)²-20x
4x²+1=(2x+1)²-4x
9x²+25=(3x+5)²-30x
4x²+25=(2x+5)²-20x
25x² + 20x + 4 = (5x +2)²
4x² + 4x + 1= (2x+1)²
9x² + 30x + 25 = (3x+5)²
4x² + 20x +25 = (2x+5)²
(4x+1)² -(2x+3)² = 16x² +8x +1 - 4x² -12x -9 = 12x² -4x -8 = 8x² +4x²-4x -8
= 8(x²-1) +4x(x-1) =8(x+1)(x-1) + 4x(x-1) =(x-1)(8x+8+4x)
= (x-1)(12x +8)
4x² + 4x + 1= (2x+1)²
9x² + 30x + 25 = (3x+5)²
4x² + 20x +25 = (2x+5)²
(4x+1)² -(2x+3)² = 16x² +8x +1 - 4x² -12x -9 = 12x² -4x -8 = 8x² +4x²-4x -8
= 8(x²-1) +4x(x-1) =8(x+1)(x-1) + 4x(x-1) =(x-1)(8x+8+4x)
= (x-1)(12x +8)