• Aug 8th 2012, 11:38 AM
AbhiKap
Hello,

I am in eight grade Math Honors and I would like some help on the following questions:

1. 5x + 9 = 2
2. 7 - 6d = 3
3. 1/3y - 2 = 4
4. 7 (10-3w) = 5(15 -4w)

This may look easy for you guys, but I don't have a lot of time and I don't know which place to post this.

Thanks, Help is appreciated.
• Aug 8th 2012, 12:17 PM
richard1234
1. Subtract 9 from both sides of the equation:

$5x = -7$

Divide both sides by 5 to get $x = -\frac{7}{5}$.

2. is done the same way.

3. is a little unclear -- do you mean $\frac{1}{3y} - 2 = 4$ or $\frac{1}{3y-2} = 4$?

4. Expand both sides to get $70 - 21w = 75 - 60w$. Bring all the $w$ terms to one side, solve for $w$.
• Aug 8th 2012, 12:30 PM
AbhiKap
Thanks. For the second one, if it is done the same way as the first one, would the answer be: D = -4/6? Also, the third one is the first one on your post. 1/3y - 2 = 4, and the two is not under the one.
• Aug 8th 2012, 12:37 PM
Deveno
Quote:

Originally Posted by AbhiKap
Thanks. For the second one, if it is done the same way as the first one, would the answer be: D = -4/6? Also, the third one is the first one on your post. 1/3y - 2 = 4, and the two is not under the one.

no, that is incorrect on the second one. you should always check your work:

if d = -4/6, then:

7 - 6d = 7 - 6(-4/6) = 7 + 4 = 11, which is not 3.

i would proceed as follows (since you appear to have trouble with "signs"):

7 - 6d = 3
7 - 6d + 6d = 3 + 6d
7 + 0 = 3 + 6d
7 = 3 + 6d
7 = 6d + 3
7 - 3 = 6d + 3 - 3

...can you continue?

by the way, this *is* the wrong section, this is "pre-college algebra" not "college algebra" (as you might have guessed from being in the 8th grade, which is not college, hmm?)
• Aug 8th 2012, 12:41 PM
richard1234