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ACT Math: Pre-Algebra Drill 4, Problem 3. Simplify the expression.
ACT Math 1.1 Pre-Algebra 1061 Views
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Description:
Pre-Algebra Drill 1, Problem 1. Calculate 2 3 + 5 3 (7 – 4).
Transcript
- 00:03
Here's your shmoop du jour...
- 00:05
Calculate 2 cubed plus 5 cubed times the quantity 7 minus 4.
- 00:10
And here are the potential answers...
- 00:14
OK, this is a total vanilla PEMDAS question.
- 00:18
PEMDAS: an awesome math mnemonic for remembering the order of operations.
Full Transcript
- 00:22
See, like this thing.
- 00:24
Like... Mary's Violet Eyes Made John Stay Up Nights Pining.
- 00:31
So... this problem tests whether we can actually use the PEMDAS mantra.
- 00:35
First we deal with the parentheses and get 7 minus 4 is 3...
- 00:40
Then we take care of the exponents... 2 to the 3rd is 2 times 2 times 2,
- 00:43
which is 4 times 2, which is 8... which is great.
- 00:48
And 5 cubed is 5 times 5 times 5, which is 25 times 5, which is 125.
- 00:55
So now we have a mere multiplication problem -- 8 plus 125 times 3.
- 01:00
Since 125 times 3 is the "M" part of PEMDAS, we have to do it before doing any addition...
- 01:07
...and we get 125 times 3, which equals 375.
- 01:13
Now add 8 to get 383.
- 01:15
And the answer is... C.
- 01:15
As in "Chocolate tastes like History."
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