Toán Lớp 8: 1 PTĐT
x² – xy – 13x -13y
2 Tìm x
x² – 8x +6 = 0
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Toán Lớp 8: 1 PTĐT
x² – xy – 13x -13y
2 Tìm x
x² – 8x +6 = 0
Comments ( 2 )
= (x²-13x)-(xy+13y)
= x(x-13)-y(x-13)
= (x-13)(x-y)
b) x²-8x+6=0
x²-2.x.4+16-10=0
(x-4)²-10=0
(x-4-√10)(x-4+√10)=0
=> \(\left[ \begin{array}{l}x-4-√10=0\\x-4+√10=0\end{array} \right.\)
=> x=4±√10