40.0k views
1 vote
Pls help, simple, and not that hard

Pls help, simple, and not that hard-example-1

1 Answer

2 votes

Answer: A) None of the above

==================================================

Step-by-step explanation:

Let's solve (x-2)(x-5) = 0 and doing so leads to x = 2 or x = 5. Plugging either value in for x makes the expression (x-2)(x-5) become 0.

Let's pick a value to the left of x = 2, let's say we pick x = 0. Plug this into the expression (x-2)(x-5) and we get the following:

(x-2)(x-5)

(0-2)(0-5)

(-2)(-5)

10

The result is a positive number, meaning that (x-2)(x-5) is positive when we select a value smaller than 2.

Now we'll repeat this with a value between 2 and 5. Let's say we pick on x = 3.

So,

(x-2)(x-5)

(3-2)(3-5)

(1)(-2)

-2

The result is negative, so (x-2)(x-5) is negative when 2 < x < 5. This immediately rules out choices C and E.

Unfortunately, answer choices B and D won't work either for similar reasoning. The only thing left is choice A.

Side note: The answer in interval notation is
(-\infty, 2] \cup [5, \infty) so basically it's everything but values between 2 and 5; however, x = 2 and x = 5 are part of the solution set.

Another side note: if you flip the inequality sign from
\ge to
\le, then the answer would be choice C.

User Jdharrison
by
8.2k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.