Question

3·(2x-1)²-(2x+1)·(2x-1)=2x+1

Answer 1

3.(4x² - 4x +1)-(4x² -2x + 2x -1) = 2x + 1 
3.(4x² - 4x +1)-4x² +2x -2x +1 = 2x + 1 
12x² - 12x + 3 -4x² +1 = 2x + 1 
8x² -12x - 2x +4 - 1 = 0 
8x² -14x +3 = 0 
Delta = b² - 4ac 
Delta = 196 - 96 
Delta = 100 

x1 = 14 - 10 / 16 = 1/4 

x2 = 14 + 10/ 16 = 3/2