2道三元一次方程组(初中的) ①a:b:c=3:4:5 a+b+c=36 ②x:y=3:2 y:z=5:4 x+y+z=66①a:b:c=3:4:5a+b+c=36②x:y=3:2y:z=5:4x+y+z=66
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![2道三元一次方程组(初中的) ①a:b:c=3:4:5 a+b+c=36 ②x:y=3:2 y:z=5:4 x+y+z=66①a:b:c=3:4:5a+b+c=36②x:y=3:2y:z=5:4x+y+z=66](/uploads/image/z/251082-18-2.jpg?t=2%E9%81%93%E4%B8%89%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%E7%BB%84%EF%BC%88%E5%88%9D%E4%B8%AD%E7%9A%84%EF%BC%89+%E2%91%A0a%EF%BC%9Ab%EF%BC%9Ac%3D3%EF%BC%9A4%EF%BC%9A5+a%2Bb%2Bc%3D36+%E2%91%A1x%EF%BC%9Ay%3D3%EF%BC%9A2+y%EF%BC%9Az%3D5%EF%BC%9A4+x%2By%2Bz%3D66%E2%91%A0a%EF%BC%9Ab%EF%BC%9Ac%3D3%EF%BC%9A4%EF%BC%9A5a%2Bb%2Bc%3D36%E2%91%A1x%EF%BC%9Ay%3D3%EF%BC%9A2y%EF%BC%9Az%3D5%EF%BC%9A4x%2By%2Bz%3D66)
2道三元一次方程组(初中的) ①a:b:c=3:4:5 a+b+c=36 ②x:y=3:2 y:z=5:4 x+y+z=66①a:b:c=3:4:5a+b+c=36②x:y=3:2y:z=5:4x+y+z=66
2道三元一次方程组(初中的) ①a:b:c=3:4:5 a+b+c=36 ②x:y=3:2 y:z=5:4 x+y+z=66
①a:b:c=3:4:5
a+b+c=36
②x:y=3:2
y:z=5:4
x+y+z=66
2道三元一次方程组(初中的) ①a:b:c=3:4:5 a+b+c=36 ②x:y=3:2 y:z=5:4 x+y+z=66①a:b:c=3:4:5a+b+c=36②x:y=3:2y:z=5:4x+y+z=66
①∵a:b:c=3:4:5
∴设a为3k,b为4k,c为5k
由题意的a+b+c=36
3k+4k+5k=36
12k=36
k=3
∴a=9,b=12,c=15
②∵x:y=3:2
∴设x为3k,y为2k
∵y:z=5:4
且y为2k,所以得z为2k×4÷5=1.6k
由题意的3k+2k+1.6k=66
6.6k=66
k=10
∴x=30,y=20,z=16
望采纳
1.设a:b:c=3:4:5=k,则a=3k,b=4k,c=5k,
a+b+c=3k+4k+5k=12k=36
解得k=3,
所以a=3k=9,
b=4k=12,
c=5k=15。
2.由题可得,x:y:z=15:10:8=k,
x=15k,y=10k,z=8k,
15k+10k+8k=33k=66,
解得k=2
所以x=30,y=20,z=16