解下列三元一次方程组(1){2x-5y=-11 ① 7y+4z=5 ② 5x+2z=2 ③}(2){3x-y+z=4 ① 2x+3y-2z=12 ② 3x+2y=66 ③}(3){3x+2y+z=14 ① x+y+z=10 ② 2x+3y-z=1 ③}(4){2x+y=42 ① 2y+z=48 ② x+2z=48 ③}(求求各位内,我要步骤
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![解下列三元一次方程组(1){2x-5y=-11 ① 7y+4z=5 ② 5x+2z=2 ③}(2){3x-y+z=4 ① 2x+3y-2z=12 ② 3x+2y=66 ③}(3){3x+2y+z=14 ① x+y+z=10 ② 2x+3y-z=1 ③}(4){2x+y=42 ① 2y+z=48 ② x+2z=48 ③}(求求各位内,我要步骤](/uploads/image/z/5472654-6-4.jpg?t=%E8%A7%A3%E4%B8%8B%E5%88%97%E4%B8%89%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%E7%BB%84%281%29%EF%BD%9B2x-5y%3D-11+%E2%91%A0+7y%2B4z%3D5+%E2%91%A1+5x%2B2z%3D2+%E2%91%A2%EF%BD%9D%282%29%EF%BD%9B3x-y%2Bz%3D4+%E2%91%A0+2x%2B3y-2z%3D12+%E2%91%A1+3x%2B2y%3D66+%E2%91%A2%EF%BD%9D%283%29%EF%BD%9B3x%2B2y%2Bz%3D14+%E2%91%A0+x%2By%2Bz%3D10+%E2%91%A1+2x%2B3y-z%3D1+%E2%91%A2%EF%BD%9D%284%29%EF%BD%9B2x%2By%3D42+%E2%91%A0+2y%2Bz%3D48+%E2%91%A1+x%2B2z%3D48+%E2%91%A2%EF%BD%9D%28%E6%B1%82%E6%B1%82%E5%90%84%E4%BD%8D%E5%86%85%2C%E6%88%91%E8%A6%81%E6%AD%A5%E9%AA%A4)
解下列三元一次方程组(1){2x-5y=-11 ① 7y+4z=5 ② 5x+2z=2 ③}(2){3x-y+z=4 ① 2x+3y-2z=12 ② 3x+2y=66 ③}(3){3x+2y+z=14 ① x+y+z=10 ② 2x+3y-z=1 ③}(4){2x+y=42 ① 2y+z=48 ② x+2z=48 ③}(求求各位内,我要步骤
解下列三元一次方程组
(1){2x-5y=-11 ① 7y+4z=5 ② 5x+2z=2 ③}
(2){3x-y+z=4 ① 2x+3y-2z=12 ② 3x+2y=66 ③}
(3){3x+2y+z=14 ① x+y+z=10 ② 2x+3y-z=1 ③}
(4){2x+y=42 ① 2y+z=48 ② x+2z=48 ③}
(求求各位内,我要步骤额,)
,不然我今晚不要睡觉了
解下列三元一次方程组(1){2x-5y=-11 ① 7y+4z=5 ② 5x+2z=2 ③}(2){3x-y+z=4 ① 2x+3y-2z=12 ② 3x+2y=66 ③}(3){3x+2y+z=14 ① x+y+z=10 ② 2x+3y-z=1 ③}(4){2x+y=42 ① 2y+z=48 ② x+2z=48 ③}(求求各位内,我要步骤
(1){2x-5y=-11 ① 7y+4z=5 ② 5x+2z=2 ③}
由③×2→10x+4z=4④-②→10x-7y=-1-①×5→18y=54→y=3
代入①→x=2再后求得z=4
(2) {3x-y+z=4 ① 2x+3y-2z=12 ② 3x+2y=66 ③
①×2-②→8x+y=20→16+2y=40-③→13x=-26→x=-2代入③→y=36
再后求得z=46
(3) {3x+2y+z=14 ① x+y+z=10 ② 2x+3y-z=1 ③}
②+③→3x+4y=11④
①-②→2x+y=4→y=4-2x⑤代入④→x=1代入⑤→y=2再后求得z=7
(4) {2x+y=42 ① 2y+z=48 ② x+2z=48 ③}
②×2-③→4y-x=48④×2+①→9y=138→y=46/3代入①→x=40/3
再后求得z=52/3