-1,-2,-2,0,6,20,(

-1,-2,-2,0,6,20,( 15 15 0 20 20 0 0 0 15 0 20 0 15 0 20 0 把 8 4 6 4 5 2 3 9 1 2 快点! 1-1/2-1/6-1/12-1/20-...-1/9900=0 1.1/6（20x+50)+2/3(5+2x)=0 2.1/2{1/2【1/2（1/2x-3）-3】-3}-3=0 行列式 1 2 3 -1 1 -1 0 20 1 0 1 0 0 -1 2 数列0,2,6,12,20,...,n(n-1)的Sn求数列0,2,6,12,20,...,n(n-1)的前n项和 1/6[20x+50]+2/3[5+2x]-1/2[4x+10]=0 一道很简单的线性代数矩阵求逆,看看哪种做法对.求矩阵的逆：3 1-2 -1解法一：3 1 1 0-2 -1 0 16 2 2 0-6 -3 0 30 1 2 3-2 -1 0 10 1 2 3-2 0 2 41 0 -1 -20 1 2 3结果为：-1 -22 3解法二：3 1 1 0-2 -1 0 11 0 1 1-2 -1 0 12 0 2道数独题目,在线等,急7 4 0 0 6 5 0 1 09 0 0 0 0 0 0 6 00 0 3 9 0 4 0 0 02 0 0 0 0 0 0 4 06 0 4 0 0 0 1 0 70 9 0 0 0 0 0 0 30 0 0 3 0 5 6 0 00 1 0 0 0 0 0 0 80 7 0 0 2 8 0 5 10 0 0 0 3 0 0 7 43 0 0 0 0 0 5 9 00 0 0 8 0 9 0 0 20 7 0 5 0 0 9 3[x-2(x-1/2)]=4x,1/6(20x+50)+2/3(5+2x)=0 1/2{1/2[1/2(1/2x-3)-3]-3}-3=0 2+2+5+0+4+1+6+8+2+6 x(x+2)(x+6)+20x+6=0 解方程(x-1)(x+2)(x+3)(x+6)+20=0 3/10(20-x)-1/2(6+13x/5)=0 1,2,3,6,11,20,37,( ) . 1,2,3,6,11,20,37,( ) . (2x-1)^2+(1-2x)-6=0 3矩阵乘积,1 -1 2 -1 2 2 20 1 1 -13 0 -1 -2