c1+c2+c3+c4+c515 2 3 4 5 15 3 4 5 1 15 4 5 1 2 15 5 1 2 3 15 1 2 3 4r5-r4,r4-r3,r3-r2.r2-r115 2 3 4 5 0 1 1 1 -4 0 1 1 -4 1 0 1 -4 1 1 0 -4 1 1 1按第1列展开= (-1)^(1+1)* 15 *1 1 1 -41 1 -4 11 -4 1 1-4...