She is incorrect cause if we take the number 20 and take 25% of it it equals 5 so now 20 is only 15. They if we take 75% away from 20 is equals 15 so then we only have 5 from 20 left. Therefore she’s incorrect because 75% leaves 5/20 and 25% leaves 15/20. Hope that makes sense.
The number of units produced by the worker during t hours of work can be modelled by the following function:

To find the number of units produced during first 3 hours, we can substitute 3 for t. This will give us the number of units produced by the worker during first 3 hours.

Thus the worker will produce 67 units during the first 3 hours of the work.
the standard form of a quadratic is simply the equation with all variables and constant on the left-hand-side.
y = 3x² <--- general form
-3x² + y = 0 <--- standard form.
3x + 5x + 7x = 180
15x = 180
x = 180/15
x = 12
Largest angle = 7x = 7*12 = 84°