We could use Algebra for this question but it’s quite simile so won’t need it. If Amanda is 25, when we add on 5 years she’ll be 30. Now it says when she’s 30, she will be twice as old as Simone. Implying that Simone will be half of Amanda’s age. In this case 30/2 = 15. So Simone must be 15.

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2 years ago

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Arthur drops a ball from a height of 81 feet above the ground. Its height, h, is given by the equation h = –16t2 + 81, where t i

Lorico [155]

Answer:

Step-by-step explanation:

We are given the position function and need to find the value of t when h<17.

Create an inequality that represents this situation:

$-16t^2+81$ The "less than" sign makes this very specifically a conjunction problem as opposed to a disjunction. That's important to the solution. But we'll get there.

The simplest way to solve this is to subtract 81 from both sides:

$-16t^2$ then divide both sides by -16:

$t^2>4$ Notice now that the sign is facing the other way since we had to divide by a negative number. Now it's a disjunction. The solution set to this inequality is that t>2 or t<-2. First and foremost, time will never be negative, so we can disregard the -2. Even if that was t<2, the more time that goes by, the greater the time interval is, not the lesser. It's the "<" that doesn't make sense, not only the -2. The solution to this inequality is