Question

62-()+13=28计算过程？

Answer 1

62-()+13=28计算过程
解析：
62-()+13=28
62-()=28-13
62-()=15
()=62-15
()=47

Answer 2

计算五个行列式太麻烦了。我手动计算一个“系数行列式”，然后用excel计算其他的，好吗？ D=|(2,-3,1,-1)(3,1,1,1)(4,-1,-1,-1)(-2,-1,1,1)|=|( 0,-3,1,-1)(7,0,0,0)(0,-1,-1,-1)(0,-1,1,1)| [r2+r3,r1-(2/7)r2,r3-(4/7)r2,r4+(2/7)r2]=|(7,0,0,0)(0,-4,2, 0)(0,2,0 ,0)(0,-1,1,1)| [r1交换r2,r2+r4,r3+r4,提出r3公因数]=-|(7,0,0,0)(0,2,0 ,0)(0,-4,2,0) (0,-1,1,1)| [交换r2,r3]=-28D1=|(3,-3,1,-1)(0,1 ,1,1)(7,-1,-1,-1)(-5,-1, 1,1)|=-28D2=|(2,3,1,-1)(3,0,1 ,1)(4,7,-1,-1)(-2,-5,1,1 )|=0D3=|(2,-3,3,-1)(3,1,0,1) (4,-1,7,-1)(-2,-1,-5,1)| =28D4=|(2,-3,1,3)(3,1,1,0)(4, -1,-1,7)(-2,-1,1,-5)|=56∴ x1=D1/D=1, x2=0, x3=-1, x4=-2

Answer 3

应该是用等号两边先减去13，这样是右边等于15，然后用62减去15，结果是47

Answer 4

13移到右边，然后32移到右边，然后整体除以-1就知道答案了

Answer 5

62-(）+13＝28，相当于解方程62-x+13＝28，x=62+13-28，x=47