D
3
=
∣
1
1
1
x
1
x
2
x
3
x
1
2
x
2
2
x
3
2
∣
D_3= \begin{vmatrix} 1 & 1 & 1 \\ x_1 & x_2 & x_3 \\ x_1^2 & x_2^2 & x_3^2 \end{vmatrix}
D3=∣
∣1x1x121x2x221x3x32∣
∣
D
3
=
r
2
(
−
x
1
)
+
r
3
∣
1
1
1
x
1
x
2
x
3
0
x
2
(
x
2
−
x
1
)
x
3
(
x
3
−
x
1
)
∣
D_3\xlongequal{r_2(-x_1)+r_3} \begin{vmatrix} 1 & 1 & 1 \\ x_1 & x_2 & x_3 \\ 0 & x_2(x_2-x_1) & x_3(x_3-x_1) \end{vmatrix}
D3r2(−x1)+r3∣
∣1x101x2x2(x2−x1)1x3x3(x3−x1)∣
∣
D
3
=
r
1
(
−
x
1
)
+
r
2
∣
1
1
1
0
x
2
−
x
1
x
3
−
x
1
0
x
2
(
x
2
−
x
1
)
x
3
(
x
3
−
x
1
)
∣
D_3\xlongequal{r_1(-x_1)+r_2} \begin{vmatrix} 1 & 1 & 1 \\ 0 & x_2-x_1 & x_3-x_1 \\ 0 & x_2(x_2-x_1) & x_3(x_3-x_1) \end{vmatrix}
D3r1(−x1)+r2∣
∣1001x2−x1x2(x2−x1)1x3−x1x3(x3−x1)∣
∣
D
3
=
∣
x
2
−
x
1
x
3
−
x
1
x
2
(
x
2
−
x
1
)
x
3
(
x
3
−
x
1
)
∣
D_3= \begin{vmatrix} x_2-x_1 & x_3-x_1 \\ x_2(x_2-x_1) & x_3(x_3-x_1) \end{vmatrix}
D3=∣
∣x2−x1x2(x2−x1)x3−x1x3(x3−x1)∣
∣
D
3
=
(
x
2
−
x
1
)
∣
1
x
3
−
x
1
x
2
x
3
(
x
3
−
x
1
)
∣
D_3=(x_2-x_1) \begin{vmatrix} 1 & x_3-x_1 \\ x_2 & x_3(x_3-x_1) \end{vmatrix}
D3=(x2−x1)∣
∣1x2x3−x1x3(x3−x1)∣
∣
D
3
=
(
x
2
−
x
1
)
(
x
3
−
x
1
)
∣
1
1
x
2
x
3
∣
D_3=(x_2-x_1)(x_3-x_1) \begin{vmatrix} 1 & 1 \\ x_2 & x_3 \end{vmatrix}
D3=(x2−x1)(x3−x1)∣
∣1x21x3∣
∣
D
3
=
(
x
2
−
x
1
)
(
x
3
−
x
1
)
(
x
3
−
x
2
)
D_3=(x_2-x_1)(x_3-x_1)(x_3-x_2)
D3=(x2−x1)(x3−x1)(x3−x2)
D
3
=
∏
1
⩽
j
<
i
⩽
3
(
x
i
−
x
j
)
D_3=\prod_{1\leqslant j<i\leqslant 3}(x_i-x_j)
D3=1⩽j<i⩽3∏(xi−xj)
10-10
4563
