If the x-coordinate of a point `P` on the join of `Q(22,1)a n dR(5,1,-2)i s4,` then find its `z-` coordinate.

Explanation

`frac{x-2}{5-2}=frac{y-2}{1-2}=frac{z-1}{-2-1}`

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Rightarrow frac{x-2}{3}=frac{y-2}{5-1}=frac{z-1}{-3}`

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x=4 Rightarrow z= ? `

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therefore frac{4-2}{3}=frac{z-1}{-3} Rightarrow-2=z-1`

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Rightarrow z=-1`

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