We can do this easily using 0s.
(x - i) (x + i) (x + 4) (x - 1) = 0
If you plug in any of the numbers, you'll get 0, making the equation true.
Answer: 6 students
What we know:
Students: 24
Students who play checkers:
Students who also play sudoku: of the
24 ÷ 3 = 8, so 8 × 2 = 16 (students who play checkers)
× 2 =
So the answer is,
6 students play both checkers and sudoku
so the 5 gallons ones is 40% acid, how much acid solute is in it anyway? well just 40% of 5 or namely 0.4*5 = 2 gallons.
the 3 gallons one is 50%, likewise it has 0.50 * 3 = 1.5 gallons of acid solute in it.