Question #29

Friday, November 6, 2009
Hello, this is Melanie. I was assigned Question #29 on Page 62.

Here is the question:

Add one pair of parentheses or square brackets to the left side of each equation to make a true statement.
a) 3.5 x 4.1 - 3.5 - 2.8 = -0.7
b) 2.5 + (-4.1) + (-2.3) x (-1.1) = 4.29
c) -5.5 - (- 6.5) divided by 2.4 + (-1.1) = -0.5

(HINT-HINT: When it says "to the left side of each equation," it simple means, to the left of the equal sign.)

An equation is different that an expression.

equation = math sentence that does have an equal sign
expression = math sentence that does not have an equal sign

eg. equation: x+y=7
expression: x+y

These kinds of questions have a lot of steps to find the answer.
The method that was taught to me was called, "Guess and Check."
It simply means what it says. You guess, and then check if it's right. If it's wrong, you just guess again, and so on.
I'm not really sure if there is a better method on finding the answer, but if you do, please tell me in the comment box.
Thanks (:

Here are the answers:

a) -0.7 = 3.5 x (4.1 - 3.5) - 2.8
-0.7 = 3.5 x (0.6) - 2.8
-0.7 = 2.1 - 2.8
-0.7 = -0.7

b) 4.29 = [2.5 + (-4.1) + (-2.3)] x (-1.1)
4.29 = (-3.9) x (-1.1)
4.29 = 4.29

c) -0.5 = -5.5 - (-6.5) divided by [2.4 + (-1.1)]
-0.5 = -5.5 + 6.5 divided by [2.4 + (-1.1)]
-0.5 = -5.5 + 6.5 divided by 1.3
-0.5 = -5.5 + 5
-0.5 = -0.5

Honestly, I don't really like this question, because it's too easy and at the same time, it's too hard. It's easy, because you don't have to explain much, but it's hard, because there isn't really an easy method to get the answer. If your confused, I'm really sorry. If you're still having a hard time with this question, just see Mr.B, and I'm sure he'll explain it way more clearly than I am, right now.

But anyways, thanks for checking out my post, and please leave a comment.
And if you find any mistakes, or if I left anything out, or if you have some kind of recommendation, feel free to tell me (:
Thanks again (;


linda 9-05 said...

Hey Melanie! Good effort in trying to explain the question, since there wasn't much to explain. I think a better term for "Guess and Check" would be "Process of Elimination" but that's just my opinion. Remember that we use different colours to make certain (and usually important) terms or phrases stand out. But the bottom line is you did a great post! Nice work!

simran 9-05 said...

Great Job! Well on thing was when you were explaining what and equation and a expression was, instead of using the same colour to bold does or does not, you could have used different ones. But that's not really a mistake. Besides that well done! :)

kara 9-05 said...

Nice work Melanie! I liked the fact that you used a lot of different colours for this post, and I also think that the "Guess and Check" method is a good method to use if you have the time.

melanie905 said...

Thanks for the suggestions you guys! I'll try to put less colour in them Linda, and I agree with "Process of Elimination." Way better than "Guess and Check." Also, thanks Simran, for pointing that out. I will do that next time. And thanks for the comment Kara! Thanks to you three (:

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