Answer:
Her answer is wrong because she the object cannot hit the ground at negative seconds. She could’ve have used other methods because she used the quadratic formula. The advantages is that it works for every situation. The disadvantages is that it takes longer. She should’ve used a different method.
Step-by-step explanation:
Answer:
(x -2) (x- 8) (x+7)
Step-by-step explanation:
Let x be the amount (the volume in milliliters) of the 5% solution to be mixed.
Then the volume of the 1% solution is 100-x milliliters.
Then your "concentration" equation is
%280.01%2A%28100-x%29+%2B+0.05%2Ax%29%2F100 = 0.02,
or, equivalently,
100-x + 5*x = 200,
which implies
4x = 100 ----> x = 100%2Fx = 25.
Answer: 25 milliliters of the 5% solution must be mised with 100-25 = 75 milliliters of the 1% solution.