Answer:
![BC=30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7oy3ei5b0en5vpva4sol7tkn4amsqlnpvm.png)
Explanation:
Given: Points A, B, and C are collinear. B lies between A and C.
,
, and
![\text{BC}=3x+6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/818f5jeo5jz5zx100yel5bss1xbp369asn.png)
To find: BC
Solution: It is given that Points A, B, and C are collinear. As B is between A and C. So, we have
![AB+BC=AC](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uz5ohbqh2kp7v9fqvkkmqboi035mirl702.png)
Here,
,
, and
So,
![2x+2+3x+6=48](https://img.qammunity.org/2020/formulas/mathematics/middle-school/g08olcgdha68mu0pk2qgqew67fgbv9s845.png)
![\implies5x+8=48](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kt28c2xx1wvad8i1xe4xqlmruf572p0pf6.png)
![\implies 5x=48-8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ljb6p1indtrqzx69vpmgs2u8a46690jk6a.png)
![\implies 5x=40](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gbwp4gn2m7occk8aqb1hq3zy49p2itm6gl.png)
![\implies x=(40)/(5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gpgqvo7iqp8qdxocep4tgtupr0nd5gfp94.png)
![\implies x=8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/j5urnpng8zsln01uril2ecs24ova5wyhmo.png)
Now, BC is
![3x+6](https://img.qammunity.org/2020/formulas/mathematics/high-school/9jyprvw5vd6ediqpt91e0xd78tbrtcoc9p.png)
On putting
in
![BC=3(8)+6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lm56dsrzxn3ytrwzcj4hahc6h6th1ic330.png)
![BC=24+6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xv5fbu80bvoai4g1ldmj4v56htpzz7jkg6.png)
![BC=30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/7oy3ei5b0en5vpva4sol7tkn4amsqlnpvm.png)
Hence, BC is 30.