The solution to a system of equations is the point at which the two lines intersect. Lines A and B intersect at point (4,4). This means (4,4) is the point which makes both equations true for the same values. The correct answer is "(4, 4) is the solution to both lines A and B."
Since there are 25 students and there’s 21 at the zoo you would end up having 21 out of 25 and 21 out of 25 as a percentage is 84% because you have to look at 25 as a whole and that whole would be 100% so 84 out of 100% is equal to 21 out of 25