Question

3·(2x-1)²-(2x+1)·(2x-1)=2x+1

Answer 1

3·(2x-1)²-(2x+1)·(2x-1)=2x+1
3(4x² -4x +1)- [(2x)²-(1²)] = 2x +1
12x² - 12x+ 3 -[4x² - 1] = 2x+1
12x² - 12x +3 -4x² + 1 - 2x - 1 = 0
8x² - 14x +3 =0

Δ= 14² -4(8)(3) = 196 - 96=100
√Δ= √100 = 10
x' = (14+10)/16 = 24/16 = 3/2
x"= (14-10)/16 = 4/16 = 1/4
 S=(1/4, 3/2)