19
If she has already watched 1.5 hours and she can only watch 5 hours per week, then we have the inequality:
1.5 + T ≤ 5
where T is is the number of hours she can watch more before reaching her limit
20
If he needs 100 points, already has 40 and earns 2 for every movie, we have the inequality:
40 + 2m ≥ 100
where m is the number of movies he needs to watch
21
We can have the equation:
x + 1 = x + 2 - 1
This would result to:
x + 1 = x + 1
which have the same terms on both sides.
Further, the equation would be:
0 = 0
Largest integer: 57
x + x + 1 + x + 2 = 168
3x + 3 = 168
-3 -3
3x = 165
/3 /3
x = 55
x = smallest integer = 55
x + 1 = middle integer = 55 + 1 = 56
x + 2 = largest integer = 55 + 2 = 57