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Teachers & SchoolsACT Math: Pre-Algebra Drill 4, Problem 1. What could the number described in the video be?

ACT Math | Pre-Algebra |

ACT Mathematics | Pre-Algebra |

Basic Operations | Absolute Value |

Foreign Language | Arabic Subtitled Chinese Subtitled Korean Subtitled Spanish Subtitled |

Language | English Language |

Pre-Algebra | Absolute value Absolute value and ordering numbers by value |

Product Type | ACT Math |

Alright, it's a bit wordy, but let's just write this out in math-ese...

It says... take the absolute value -- that's these straight line thingies...

It says "of"... anything "of" is gonna go inside the straight line thingies -- so

that quantity is...

2x minus seven.

See how we did that? Just kinda reversed the order there.

Then this whole absolute value thing equals 1.

So what are the numbers that could fulfill this solution for x?

Well, maybe we just start with the answer set they give us. Could it be A, which is

negative 4? Well, let's try it.

We have 2 times negative 4, which is negative 8... then we subtract 7 to get negative 15...

which, uh... does not equal 1. At least not in the U.S. Choice A can go bye-bye.

Alright, let's try B... 3.

2 times 3 is 6; subtract 7 to get negative 1... but we are taking the absolute value

here so it's... just 1.

Yeah, 3 works. So the answer is either B or E; we'll have to try C, or 4, to be sure.

If we plug in 4 for x we get 2 times 4, which is 8... then subtract 7, and we have 1.

The absolute value thingy doesn't matter for positive numbers so yeah -- x equals 1 here.

C is true as well, so the answers are both B and C or in this problem...

...the answer is E.

As in, "Evil troll."