a/ [tex]\fn_cm x^{2}-7x+6=0[/tex]
b/ [tex]\fn_cm 4x^{2}-8x+3=0[/tex]
a) [TEX]x^2 - 7x + 6 = 0[/TEX]
[TEX]x^2 - x - 6x + 6 = 0[/TEX]
[TEX]x(x - 1) - 6(x - 1) = 0[/TEX]
[TEX](x - 6)(x - 1) = 0[/TEX]
Suy ra : [TEX]x = 1[/TEX] hoặc [TEX]x = 6[/TEX]
b) [TEX]4x^2-8x+3=0[/TEX]
[TEX]4x^2 - 2x - 6x + 3 = 0[/TEX]
[TEX]2x(2x - 1) - 3(2x - 1) = 0[/TEX]
[TEX](2x - 1)(2x - 3) = 0[/TEX]
Suy ra :[TEX]2x - 1 = 0[/TEX] hoặc [TEX]2x - 3 = 0[/TEX]
Hay [TEX]x =\dfrac{1}{2}[/TEX] hoặc [TEX]x = \dfrac{3}{2}[/TEX]