Thread: Final Exam Review - Help

1. Final Exam Review - Help

Below are the questions i'm having trouble with on my review. PLEASE HELP!! I'm pulling my hair out.

1. 1/8 (16y+8) - 17 = -1/4 (8y-16)

2. 2[9-3(-2x-4)] = 12x + 42

I'm sure i will have more as the review has 60 questions.. but if someone could get me over these two it would be much appreciated.

Thanks,

DEMPC

2. Originally Posted by dempc
Below are the questions i'm having trouble with on my review. PLEASE HELP!! I'm pulling my hair out.

1. 1/8 (16y+8) - 17 = -1/4 (8y-16)

2. 2[9-3(-2x-4)] = 12x + 42

I'm sure i will have more as the review has 60 questions.. but if someone could get me over these two it would be much appreciated.

Thanks,

DEMPC
For both of these, I take it we need to solved for the variable?

In (1), note that when you apply the distributive law to both sides, we have $\displaystyle \tfrac{1}{8}\left(16y\right)+\tfrac{1}{8}\left(8\r ight)-17=-\tfrac{1}{4}\left(8y\right)-\tfrac{1}{4}\left(-16\right)\implies 2y+1-17=-2y+4$ $\displaystyle \implies 2y-16=-2y+4$

Can you continue from here and solve for y?

In (2), apply distributive law to get $\displaystyle 2\left(9\right)+2\left(-3\left(-2x-4\right)\right)=12x+42\implies 18-6\left(-2x-4\right)=12x+42$

Now apply distributive law again to have $\displaystyle 18-6\left(-2x\right)-6\left(-4\right)=12x+42\implies 18+12x+24=12x+42\implies 12x+42=12x+42$. This means that $\displaystyle x$ can take on infinitely many values.

Does this make sense?

3. i can't see the latex on the first question. it says Latex too big 600x200

4. $\displaystyle \tfrac{1}{8}(16y+8)-17=-\tfrac{1}{4}(8y-16)$

Expand

$\displaystyle \tfrac{1}{8}\left(16y\right)+\tfrac{1}{8}\left(8\r ight)-17=-\tfrac{1}{4}\left(8y\right)-\tfrac{1}{4}\left(-16\right)$

$\displaystyle 2y+1-17=-2y+4$

$\displaystyle 2y-16=-2y+4$

Group like terms

$\displaystyle 4y=20$

$\displaystyle y=5$

5. thank you to both of you guys!!... still pulling my hair out over the review.. but this helps so much!!

Really appreciate it!

DEMPC

6. Originally Posted by dempc
thank you to both of you guys!!... still pulling my hair out over the review.. [snip]
All for the good - a little bit of pain will keep you awake.