Let x be the cash Desmond is going to need, since he already has $5, the total amount he will need is:
![x+5](https://img.qammunity.org/2023/formulas/mathematics/high-school/wwkl6s28rzxdl2aucen1xtlw6mu9gb24f4.png)
and he wants this to be at least $50, hence we have the inequality:
![x+5\ge50](https://img.qammunity.org/2023/formulas/mathematics/college/iuadk22j7czt8fpq5wnmitclckubj8ido0.png)
Let's solve it:
![\begin{gathered} x+5\ge50 \\ x\ge50-5 \\ x\ge45 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ohce283ftkzw4zqomb8t4s3ewk7vlpiopu.png)
Therefore he at least has to put $45 dollars more in his wallet, that is:
![x\ge45](https://img.qammunity.org/2023/formulas/mathematics/college/uikfx4jd5y6c8lxmydd60g9k78k16esc8g.png)
The solution in interval form is:
![\lbrack45,\infty)](https://img.qammunity.org/2023/formulas/mathematics/college/ugwkcmf2zi2qudl7jq6klet1hn2sj7i2up.png)