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primary 6 | Maths
| Algebra
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hi.. i don’t understand this equation.. may someone explain this to me thank u
Date Posted: 1 year ago
Views: 261
8 - 6x + 2 + 9x
You can think of “x” as a unit.
How do you simplify this? (When I write simplify, I mean to make the above “shorter-looking”).
You did well in arranging the terms to become 8 + 2 - 6x + 9x.
The 8 + 2 is equal to 10, yes. But how about the -6x + 9x?
As you know it by now, you cannot combine 10 - 6x to become 4x. So, we will leave the 10 alone.
——————————
Now, look at -6x + 9x. It appears like -6 + 9, although there is an “x” involved. Simplifying -6x + 9x is like combining -6 + 9. But what does it become?
Seeing negative numbers is definitely something unfamiliar for you as you will only face proper negative numbers in secondary education.
-6 + 9 is like saying, I first lose 6 marbles, then suddenly I gain 9 marbles.
The overall gain is 3 marbles (you can tell this easily by counting the marbles accordingly). So, -6 + 9 = 3.
With the “x” present, it becomes -6x + 9x = 3x.
[You can use a number line as well if you know what they are, but you can check with a teacher on how to input “negative numbers” in a number line]
——————————
Putting all together,
8 - 6x + 2 + 9x
= 8 + 2 - 6x + 9x
= 10 + 3x
You can think of “x” as a unit.
How do you simplify this? (When I write simplify, I mean to make the above “shorter-looking”).
You did well in arranging the terms to become 8 + 2 - 6x + 9x.
The 8 + 2 is equal to 10, yes. But how about the -6x + 9x?
As you know it by now, you cannot combine 10 - 6x to become 4x. So, we will leave the 10 alone.
——————————
Now, look at -6x + 9x. It appears like -6 + 9, although there is an “x” involved. Simplifying -6x + 9x is like combining -6 + 9. But what does it become?
Seeing negative numbers is definitely something unfamiliar for you as you will only face proper negative numbers in secondary education.
-6 + 9 is like saying, I first lose 6 marbles, then suddenly I gain 9 marbles.
The overall gain is 3 marbles (you can tell this easily by counting the marbles accordingly). So, -6 + 9 = 3.
With the “x” present, it becomes -6x + 9x = 3x.
[You can use a number line as well if you know what they are, but you can check with a teacher on how to input “negative numbers” in a number line]
——————————
Putting all together,
8 - 6x + 2 + 9x
= 8 + 2 - 6x + 9x
= 10 + 3x
You have to be very careful with how you deal with negative numbers.
I give you another example.
7 - 3k - 6k
What does this become?
[If you guessed it correctly, it’s 7 - 9k]
- 3k - 6k is like saying, I lose 3 marbles and then proceed to lose another 6 marbles, so I lose a total of 9 marbles.
I give you another example.
7 - 3k - 6k
What does this become?
[If you guessed it correctly, it’s 7 - 9k]
- 3k - 6k is like saying, I lose 3 marbles and then proceed to lose another 6 marbles, so I lose a total of 9 marbles.
ohh oky ty i understand btr now
See 1 Answer
done
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When you re-arrange the terms, keep in mind that the +/-/×/÷ in front will always stick with the term.
After re-arranging the terms, add or subtract the whole number terms together and the x terms together.
After re-arranging the terms, add or subtract the whole number terms together and the x terms together.
Date Posted:
1 year ago
Actually, you missed his point.
From my observations, the student lacks the understanding on the section “-6x + 9x”. His re-arrangement of terms appears ok.
From my observations, the student lacks the understanding on the section “-6x + 9x”. His re-arrangement of terms appears ok.
Thanks for pointing that out. Your explanation is much better.
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