已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 急已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 求x+y+z的值将原方程组整理得:{ 2(x+3y)+(x+y+z)=3.15①3(x+3y)+(x+y+z)=4.20②①×3,得6(x+3y)+3(x+y+z)=9.45③ ②×2,得6(x+3y)+2(x+y+z)=
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![已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 急已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 求x+y+z的值将原方程组整理得:{ 2(x+3y)+(x+y+z)=3.15①3(x+3y)+(x+y+z)=4.20②①×3,得6(x+3y)+3(x+y+z)=9.45③ ②×2,得6(x+3y)+2(x+y+z)=](/uploads/image/z/392783-23-3.jpg?t=%E5%B7%B2%E7%9F%A5%E6%96%B9%E7%A8%8B%E7%BB%84+%7B3x%2B7y%2Bz%3D3.15+4x%2B10y%2Bz%3D4.20+%E6%80%A5%E5%B7%B2%E7%9F%A5%E6%96%B9%E7%A8%8B%E7%BB%84+%7B3x%2B7y%2Bz%3D3.15+4x%2B10y%2Bz%3D4.20+%E6%B1%82x%2By%2Bz%E7%9A%84%E5%80%BC%E5%B0%86%E5%8E%9F%E6%96%B9%E7%A8%8B%E7%BB%84%E6%95%B4%E7%90%86%E5%BE%97%EF%BC%9A%7B+2%28x%2B3y%29%2B%28x%2By%2Bz%29%3D3.15%E2%91%A03%28x%2B3y%29%2B%28x%2By%2Bz%29%3D4.20%E2%91%A1%E2%91%A0%C3%973%2C%E5%BE%976%28x%2B3y%EF%BC%89%2B3%EF%BC%88x%2By%2Bz%29%3D9.45%E2%91%A2+%E2%91%A1%C3%972%2C%E5%BE%976%28x%2B3y%EF%BC%89%2B2%EF%BC%88x%2By%2Bz%29%3D)
已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 急已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 求x+y+z的值将原方程组整理得:{ 2(x+3y)+(x+y+z)=3.15①3(x+3y)+(x+y+z)=4.20②①×3,得6(x+3y)+3(x+y+z)=9.45③ ②×2,得6(x+3y)+2(x+y+z)=
已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 急
已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 求x+y+z的值
将原方程组整理得:
{ 2(x+3y)+(x+y+z)=3.15①
3(x+3y)+(x+y+z)=4.20②
①×3,得6(x+3y)+3(x+y+z)=9.45③
②×2,得6(x+3y)+2(x+y+z)=8.40④
③-④得x+y+z=1.05
按照上述方法,已知方程组{x+y+z=11
x-3y-z=1
试求x+0.5z的值
已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 急已知方程组 {3x+7y+z=3.15 4x+10y+z=4.20 求x+y+z的值将原方程组整理得:{ 2(x+3y)+(x+y+z)=3.15①3(x+3y)+(x+y+z)=4.20②①×3,得6(x+3y)+3(x+y+z)=9.45③ ②×2,得6(x+3y)+2(x+y+z)=
x+y+z=11
x-3y-z=1
将原方程组整理得:
y+0.5z+(x+0.5z)=11 ①
-3(y+0.5z)+(x+0.5z)=1 ②
①×3,得 3(y+0.5z)+3(x+0.5z)=33 ③
③+②,得 x+0.5z=17/2