20=(2x+1)(x+6)* 1/2

40=(2x+1)(x+6) 40=2x²+12x+x+6 2x²+13x-34=0 Δ=441 √Δ=21 x₁=-13-21/4 = -8,5 x₂=-13+21/4= 2

20=(2x+1)(x+6)* 1/2 20=(2xkwadrat + 12x + x + 6 )1/2 20=xkwadrat + 6x + 1/2 +3 xkwadrat - 6 1/2 x=-17/ (-1) x(x+6 1/2 ) = 17/x x+6 1/2= 17/x x=17/x-13/2 x-17/x=-6 1/2 -16/x=-6 1/2 / (-1) 16/x=13x 32=13x x=2 6/13