For this case we must find the point that Harold used to arrive at the following equation:
![y = 3 (x-7)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/unwerix9kt8t67r39h70eg7rqxcwnot2t7.png)
Starting from the fact that the equation of the point-slope form of a line is given by:
![(y-y_ {1}) = m (x-x_ {1})](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jdxovkddssug7p2qsvhtvf5xhrq531q03c.png)
If we compare the standard equation with Harold's, we see that the slope of the line is
![m = 3.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/293zf58d59r6ucvpckfi5qwk0urh4ih3f5.png)
In addition, it is observed that
and
![y_ {1} = 0.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gt2tos813w1lt6xbe3w5ewrhuknsv53hrz.png)
Then, the correct option is: Harold used the point (7,0)
ANswer:
When Harold wrote his equation, the point was used (7,0).