Theo giả thiết, ta có: `x/2=y/3⇒x/8=y/12` `(1)`
`y/4=x/7⇒y/12=z/21` `(2)`
Từ `(1)` và `(2)`, suy ra: `x/8=y/12=z/21`
Áp dụng tính chất của dãy tỉ số bằng nhau, ta có:
`x/8=y/12=z/21=(2x)/16=(2x-y+z)/(16-12+21)=50/25=2`
`⇒x=2.8=16; y=2.12=24; z=2.21=42`
Vậy `x=16; y=24; z=42`.
Đáp án:
`x=16;y=24;z=42`
Giải thích các bước giải:
Ta có:`x/2=y/3<=>x/8=y/12``y/4=z/7<=>y/12=z/21``=>x/8=y/12=z/21`Áp dụng tính chất của dãy tỉ số bằng nhau ta có:`x/8=y/12=z/21=(2x-y+z)/(2.8-12+21)=50/25=2`Do đó:`x/8=2=>x=8.2=16``y/12=2=>y=12.2=24``z/21=2=>z=21.2=42`Vậy `x=16;y=24;z=42`
Giúp với đề trên đề bài là chọn câu trả lời A,B,C,D
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