Answer:
360 feet long.
Step-by-step explanation:
We have been given that a football field is 100 yards and also includes two end zones that are 10 yards long each.
Let us find the length of both end zones by multiplying 10 by 2 as field includes to end zones.
![\text{The length of both end zones}=2* 10\text{ yards}](https://img.qammunity.org/2020/formulas/mathematics/high-school/7oou2melo2enncivz03yrd1fwkw9zkj2pe.png)
![\text{The length of both end zones}=20\text{ yards}](https://img.qammunity.org/2020/formulas/mathematics/high-school/lya9kritzqpwvbv10m1fzgdfr4r9z7bwcp.png)
To find the total length of football field we will add the length of both end zones to the length of football field.
![\text{The total length of football field including the end zones}=(100+20)\text{ yards}](https://img.qammunity.org/2020/formulas/mathematics/high-school/55sib0dv170e9c25x5l0v3lf0ve921r7gi.png)
![\text{The total length of football field including the end zones}=120\text{ yards}](https://img.qammunity.org/2020/formulas/mathematics/high-school/hlc8645itjceprjci6md8ax92zvq4fue5h.png)
Let us convert 120 yards to feet by multiplying 120 by 3 as 1 yard equals to 3 feet.
![\text{The total length of football field including the end zones}=120\text{ yards}* \frac{3\text{ feet}}{\text{yard}}](https://img.qammunity.org/2020/formulas/mathematics/high-school/95turl90ghvslsk9asc3benbw5ygpoecaz.png)
![\text{The total length of football field including the end zones}=120* 3\text{ feet}](https://img.qammunity.org/2020/formulas/mathematics/high-school/t3ydxewvpglys96dlqetpd5bd98z428dh6.png)
![\text{The total length of football field including the end zones}=360\text{ feet}](https://img.qammunity.org/2020/formulas/mathematics/high-school/z9wwy2lyv89oyrgmc7ajmhqnbv679gyxgt.png)
Therefore, the football field is 360 feet long including the end-zones.