First we need to calculate how many years her brother has when she is 18. As text says he is:
18/3 = 6 years old
Now when she gains another 18 years (36-18=18) he will also gain those 18 years
When she is 36 he will have 6+18=24 years old
Answer is 24.
For the first question, simply plug in the value of 3 into the polynomial question. The final answer is your volume of the hot water tub.
For the second question, you can figure out that x = -5 is not a real root because it does not touch or cross the x axis.
If it does it would be an solution.
Answer:
any number less than one multiplied by 300 would be less than 300