Explanation:
Given,
![√(x + 11) - x = - 1](https://img.qammunity.org/2021/formulas/mathematics/college/jc7u04o165alz1htqo5i6l2byexltcm959.png)
To Find:
Solution:
Square both sides, then solve.
![\rm \implies \: \: √((x + 11) ) {}^(2) = ( - 1 + x) {}^(2)](https://img.qammunity.org/2021/formulas/mathematics/college/cos4bfthpjjx9ggmtx5p0nwnbazmkw0onf.png)
![\implies \rm \: x + 11 = - (1 + x) {}^(2)](https://img.qammunity.org/2021/formulas/mathematics/college/3poe3szyioky3nmvrhllbasn668o6jr6u9.png)
![\rm \implies \: \: x + 11 = 1 - 2x + x {}^(2)](https://img.qammunity.org/2021/formulas/mathematics/college/k94fuqo5kqedyoowihgwya40iyjpdz4162.png)
![\rm \implies \: 1−2x+x {}^(2)=x+11](https://img.qammunity.org/2021/formulas/mathematics/college/brsxvm3sozsqgcnde6ewwftj6z6veowy7w.png)
![\rm \implies1+x {}^(2) −3x=11](https://img.qammunity.org/2021/formulas/mathematics/college/lbfldjjlqsze2cucefznsfkguij8wg6ygn.png)
![\rm \implies1+x {}^(2) −3x−11=0](https://img.qammunity.org/2021/formulas/mathematics/college/d9y75q7yivcngzjvkv7e1r72luw5o7xmmm.png)
![\rm \implies {x}^(2) - 3x - 10 = 0](https://img.qammunity.org/2021/formulas/mathematics/college/fi4njvhzxs2ju7mrxw46m2x8as0wxvoki6.png)
Factor the LHS
![\implies \rm \: (x - 5)(x + 2) = 0](https://img.qammunity.org/2021/formulas/mathematics/college/m5zmm9peaop7uv462eok585hdivzzt3cfg.png)
Bring terms equal to 0, that is
![\implies \rm(x - 5) = 0](https://img.qammunity.org/2021/formulas/mathematics/college/ppwgaez2wprkuxjyl5452flhejmw62pmp5.png)
![\implies \rm \: x = 5+ 0 = \boxed 5](https://img.qammunity.org/2021/formulas/mathematics/college/mvxuvemjm1kvtrnnzje3fdq1i6wx84vaax.png)
AND set x+2 equal to 0,
![\rm\implies \: x + 2 = 0](https://img.qammunity.org/2021/formulas/mathematics/college/hzslffhap8lcxk7d42frbvasmd5z24phid.png)
![\rm \implies \: x = - 2](https://img.qammunity.org/2021/formulas/mathematics/college/jkb257vy6ufqcur76f5jfrqh0xvvwo6ox0.png)
So the possible two values are 5 & -2.
But, after plugging the values for verifying each,the most accurate is 5.
So, the value of x is 5.