Question

Resolva as equações do 2º grau:

a) xº - 3y-9=0
b) 2x²+2y+2 = 0
c) x²+2y+12=0
d) 3x²+9x+27=0
e) 3x²-7x+4=0

Answer 1

a)(x+3)2=9 (x+3) (x+3)-9=0 x2+3x+3x+9-9=0 x2+6x=0 x(x+6)=0 x=0 x+6=0 x=-6. B)2x2-4x+2=0 2x2-2x=0. C)x2+2y+12=0. x2=2y+12. x2=2(y-6). x=-6. D)3x2+9x+27=0. 3x=9. x=9/3. x=3. -3×32+9×3=0. -3×9+9×3. -27+17=0. E) 3×2-7x+4=0. delt=(-7)2-4×3×4. delt 49-48. delt=1. -(-7)+-√1. 2×3. x 7+1÷6. x=7+1=8=4. 6. 6. 4. x=7-1=6-1. 6. 6