The new equation will be [tex]y=-1.5x+75[/tex]
Since the height at 0 seconds will be 75, it means that 15 has been added to the height at each time instant.
As a result, the gradient will remain [tex]-1.5[/tex], but the y-intercept will become 75. Therefore the equation will only change at the intercept.
The new equation will be [tex]y=-1.5x+75[/tex]
Learn more about slopes and intercepts: https://brainly.com/question/1201010