Question

HELP PLEASE!!! I WILL GIVE A MEDAL!!!
Part A: Solve A = 9 over 2(x + 23) for x. (4 points)
Part B: Determine the value of x when A = 108. (2 points)
Part C: Solve –np – 90 > 30 for n. Show your work. (4 points)

Answer 1

\[ A = \frac{9}{2(x+23)}\]
So what's the first step? :)

Answer 2

How could you start to get x by itself?

Answer 3

This is for part A right?

Answer 4

For C)

- np - 90 > 30

"negative np minus 90 is greater than 30"

we can add np to each side, giving us

-90 > 30 + np

"negative 90 is greater than 30 plus np"

flip the inequality around, so it reads as

np + 30 < -90

"np plus 30 is less than negative 90"

Then subtract thirty and divide by p, making sure the final answer takes the form

n < ........

"n is less than....."

Answer 5

Yeah, that first equation was for part A

Answer 6

Okay. Uh? well we have to find the variable that needs to be isolated which is "x".
Dont we have to work bacwkards with PEMDAS? @AllTehMaffs

Answer 7

Yeah. You can make your life much simpler though by making it looks like this then.

\[ (A) = \frac{(9)}{(2)(x+23)}\]
The parenthesis break things up into manageable chunks. You don't have any exponents greater than 1 so we're good there, so we can jump straight into multiplication and division.

Remember that a term in a parenthesis can be kept together, se can multiply each side right off the bat by (x+23)

\[(x+23)(A) = \frac{(9)}{(2)}\]

What's a good next step then?

Answer 8

okay um? sorry Im not very good at this so it may take me some time to figure out.

Answer 9

:) no worries. Did that first step make sense?

Answer 10

not really... why did you move (x + 23) from the right side to the left?

Answer 11

I did that to get it out of the denominator. I didn't multiply through with the 2 while it was on the bottom because later in the problem you would then have to divide by 2. ie

\[ A = \frac{9}{2(x+23)} \]
\[ A = \frac{9}{2x + 46} \]
\[ (2x + 46) A = 9 \]

if you do it that way, the 2 in front of the x will have to get divided out anyway, so might as well keep them separated in the beginning :) Does that make sense?

So yeah, the expression we're working with now is

\[ (x+23) \cdot A = \frac{9}{2} \]

Answer 12

oh.. Now I get it a little bit better. lol thankss

Answer 13

okay so that is the first part of the equation right?

Answer 14

Also, to actually *do* that, you're multiplying both sides by (x+23)

\[A = \frac{9}{2 (x+23)} \]
\[ (x+23)A = (x + 23) \left( \frac{9}{ 2(x+23)} \right) \]
\[ (x+23) A = \frac{9}{2} \cancel{ \frac{(x+23)}{(x+23)}}^{ 1} \]

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Yeah, that's the first part of the equation :) You can divide both sides by something now to isolate x even more......

Answer 15

Okay I am really really really sorry. but can you solve the equation and then after that I can see the steps because the images kind of confuse me a little bit. I am soo sorryy):

Answer 16

sure :)

\[ (x+23)A = \frac{9}{2} \]
\[ x+23 = \frac{1}{A} \frac{9}{2} \]
\[ x = \frac{9}{2A} - 23 \]

follow?

Answer 17

Yes thank you. Can I go ahead and write down these steps in my answer box?? :)(:

Answer 18

@AllTehMaffs

Answer 19

sure.... I don't know what that is, but the solution is correct ^^

Answer 20

My answer box? Its just where I write my answer down.

Answer 21

What are the answers for part b and c???