D+E+F=203(3) -1B-1C+H+K=469(4) G+H+I=570(5) B+E+L=239(6) J+K+L=885(7) C+F+I=416(8) 0 =0(9) 0 =0(10) 0 =0(11) 0 =0(12) 交After the exchange of equation (2) and equation (4), the equation system becomes: ...
2 B + C + D = 1 (3) A + 2 B + 2 C + 2 D = 1 (4)解题过程:将第(1) 等式两边 除以2后,可以得到等式: A -1 C + 1 2 D = 1 2 (5),然后再同时用第 (2) 等式两边 减去 等式(5)两边,方程组化为: 2 A -2 C + D = 1 (1) B + 2 C + 5 2 D = 3 2 (2) 2 ...