Answer:
![x=8](https://img.qammunity.org/2021/formulas/mathematics/middle-school/eubtzoilwcpy5phrh05m4p6y4hzzjhe5fz.png)
Explanation:
So we are given that ΔABC and ΔDEC are similar.
In other words, AB and DE are similar. And CA and CD are also similar.
When the sides are similar, it means that their proportions are equal to the each other. Therefore:
![(AB)/(DE)=(CA)/(CD)](https://img.qammunity.org/2021/formulas/mathematics/college/9rxudvujghx2ul368v3msv7gqnb7j2e2u8.png)
Substitute 30 for AB, 18 for DE, 2x-1 for CA and x+1 for CD. So:
![(30)/(18)=(2x-1)/(x+1)](https://img.qammunity.org/2021/formulas/mathematics/college/m8yj6ty4xcbnysdk9hv14clrpgx5ppoov3.png)
Reduce the left by dividing both layers by 6. Thus:
![(5)/(3)=(2x-1)/(x+1)](https://img.qammunity.org/2021/formulas/mathematics/college/gflul5w4ddckw0u567dxw926bk47sbmy94.png)
Cross multiply:
![3(2x-1)=5(x+1)](https://img.qammunity.org/2021/formulas/mathematics/college/7nr3wjjfua90ytaj109lbvddw2m7ldpqjs.png)
Distribute:
![6x-3=5x+5](https://img.qammunity.org/2021/formulas/mathematics/college/my982o3vawen3ujwzsombph1z09ijamec9.png)
Add 3 to both sides:
![6x=5x+8](https://img.qammunity.org/2021/formulas/mathematics/college/k1p5mabdtifp33f0pp3z8t5lshge18wsq7.png)
Subtract 5x from both sides:
![x=8](https://img.qammunity.org/2021/formulas/mathematics/middle-school/eubtzoilwcpy5phrh05m4p6y4hzzjhe5fz.png)
So, the value of x is 8.
And we're done :)