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High School Teacher
I agree with frizzyperm--we can't do your homework for you. But here is how, in general to do this type of question.
Remember that because there is an "=" sign, it means that whatever you do to one side of the equation you can do to the other, because that's what "equal" means. So for number 1, see if there is something you can do so that you only have the term with an unknown (the letter) in it. Aha, you can subract 6 from each side of the equation. That leaves you with 3y=27; if you divide each side by 3, you will get what y equals.
Posted by lynn30k on November 17, 2008 at 8:39 PM (Answer #1)
At what point does 'helping students learn' become 'doing students' homework for them' ????
Q1.) move the +6 to the right side of the equation, making it -6, so 3y = 27-6 and then continue
Q2) 5(b-6) is equal to 5b - 30
... +7b .... gives 12b - 30 = 12
move the -30 to the right side gives 12b = 42
x = ?
Q3) 3x +17 = 11x -13
move -13 to the left side...
3x +17 +13 = 11x
3x +30 = 11x
30 = 8x
? = x
Posted by frizzyperm on November 17, 2008 at 8:24 PM (Answer #2)
you got number one wrong.
you got number two wrong.
and you got number four wrong.
but you got number two right!
Posted by frizzyperm on November 18, 2008 at 1:09 AM (Answer #3)
bleah, that serves me right for pointing out other people's mistakes...
you got number three right!
Posted by frizzyperm on November 18, 2008 at 1:18 AM (Answer #4)
Elementary School Teacher
You could think about it this way:
3 times something PLUS 6 will give me 27.
Work it backwards and subtract the 6. That gives you 21.
Now think: What times 3 will give me 21?
y must equal 7 (y=7)
Sometimes, reason will help you solve problems better than formulas or rules.
Posted by amy-t on November 19, 2008 at 10:12 AM (Answer #5)
Posted by dracomath on December 28, 2008 at 1:21 AM (Answer #6)
Posted by revolution on July 17, 2010 at 6:32 PM (Answer #7)
High School Teacher
1. subtract six from six as well as 27 (this is called combining like terms) this will give you 3y=21. Then divide 3 into 3y as well as 27. This will give you 9 or y=9
2. distribute 5 into (b-6) through multiplication. This will give you 5b-6+7b=12. combine like terms 5b+7b. This will give you 12b=12. Now divide 12 from both sides. This will give you 1 or b=1
3. Realize that the like terms are on opposite sides of the equals sign so you have to use the opposite signs. Subtract the smaller number from the larger number...Start by subtracting 3x from itself as well as 11x. This will give you 17=8x-13. Now continue combining like terms and add 13 from itself as well as 17. This will give you 30=8x. Now divide 8 from 8x as well as 30. this will give you 3.75=x.
4. First cross multiply. 1(8x+110) and 5(10x+130) This will give you 8x+110=40x+650. Now combine like terms...remember to use the opposite sign because they are on different sides of the equals sign. Subtract 8 from itself as well as 40x This will give you 110=32x+650. Now subtract 650 from itself as well as 110. This will give you -540=32x. Now divide 32 from itself as well as 540. This will give you -16.875=x.
Posted by bmaruffi on November 17, 2008 at 11:50 PM (Answer #8)
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