2. Achar as raízes das equações:
2.1) x2 - 5x + 6 = 0 (R: 2, 3)
2.2) x2 - 8x + 12 = 0 (R: 2, 6)
2.3)x2+2x-8=0(R:2,-4) 2.13)x2=x+12(R:-3,4)
2.4)x2-5x+8=0(R:vazio)
2.14)2x2=-12x-18(R:-3)
2.5) 2x2 - 8x + 8 = 0 (R: 2,)
2.15)x2-x-20=0 {R:-4 e 5}
2.6)x2-4x-5=0(R:-1,5)
2.16)x2-3x+4{R:-1e4}
2.7)-x2+x+12=0(R:-3,4)
2.17)x2-14x+48=0{R:6e8}
2.8)-x2+6x-5=0(R:1,5)
2.18)x2+3x-28=0{R:-7e4}
2.9)6x2+x-1=0(R:1/3,-1/2) 2.19)x2+9=4x(R:vazio)20)
2.10)3x2-7x+2=0(R:2,1/3) 2.20)25x2=20x–4(R:2/5)
2.21)2x=15–x2(R:3,-5) 2.24)x2+5x+6=0(R:-2,-3)
2.22)x2-7x+12=0(R:3,4) 2.25)x2+5x+4=0(R:-1,-4) 2.23)7x2+x+2=0(vazio)
2.26)x2+3x–6=-8(R:-1,-2)