Answer:
![\boxed {\boxed {\sf 0}}](https://img.qammunity.org/2021/formulas/mathematics/high-school/7jbk28tzqtwzm8mhmblw9sdgx6bbv0rgpz.png)
Explanation:
We are given the expression:
![50x^3-20x+8x-21x^3-3x+15x-29x^3](https://img.qammunity.org/2021/formulas/mathematics/high-school/bi1kcjovvl01j7x9nwu6ofzaf2a65lmqiu.png)
We want to simplify it, so we must combine the like terms. For this equation, the like terms are terms with x³ or x.
First, combine all the x³ terms.
![(50x^3-21x^3-29x^3)-20x+8x-3x+15x](https://img.qammunity.org/2021/formulas/mathematics/high-school/5cdxvlq6q3hw4pud1w3l70suk0yljq44d6.png)
![(0x^3)-20x+8x-3x+15x](https://img.qammunity.org/2021/formulas/mathematics/high-school/bxl4bq1ahqwdndop6nlka8ea08usbh56gs.png)
![-20x+8x-3x+15x](https://img.qammunity.org/2021/formulas/mathematics/high-school/cs7p6qzqsnnrcqevn1itm2f8pikxf4w6wf.png)
Next, combine all the remaining terms, because they are all terms with an x.
![-12x-3x+15x](https://img.qammunity.org/2021/formulas/mathematics/high-school/dk7ftt4tk3yt5uzsoj2e9a1be2rbr8a5p4.png)
![-15x+15x=0](https://img.qammunity.org/2021/formulas/mathematics/high-school/6l6zuzah1clqkelifcs6fhi64ryhu9m88g.png)
The expression is equal to 0