Can somebody explain why you exclude this inequality please…?
P ≥ 39m
A < 99m²
P = 14X + 4
Now I understand where the values come from, but the mark scheme implies that it is obvious to exclude -11/3; anybody know why?
P ≥ 39m
A < 99m²
P = 14X + 4
- 14X + 4 ≥ 39
- 14X ≥ 35
- X ≥ 35/14
- X ≥ 5/2
- 9X² + 6X < 99
- 9X² + 6X – 99 < 0
- 3 (3X² + 2X – 33) < 0
- 3 (3X + 11)(X – 3) < 0
- -11/3 < X < 3
Now I understand where the values come from, but the mark scheme implies that it is obvious to exclude -11/3; anybody know why?