Răspuns :
(1-2x)(1+2x)+(2x+3)²-3(4x-1)=13
1 - 2 x + 2 x - 4 x² + 4 x² + 12 x + 9 - 12 x + 3 = 13
- 2 x + 2 x = 0
- 4 x² + 4 x²= 0
+ 12 x - 12 x = 0
1 + 9 + 3 = 13
1 - 2 x + 2 x - 4 x² + 4 x² + 12 x + 9 - 12 x + 3 = 13
- 2 x + 2 x = 0
- 4 x² + 4 x²= 0
+ 12 x - 12 x = 0
1 + 9 + 3 = 13
(1-2x)(1+2x)+(2x+3)²-3(4x-1)=13
1 - 4x² + 4x² + 12x + 9 - 12x + 3 = 13
1 + 9 + 3 = 13 ( adevarat )
1 - 4x² + 4x² + 12x + 9 - 12x + 3 = 13
1 + 9 + 3 = 13 ( adevarat )