Are these correct and help with one D = C-s/n (solve for s)?

Question

This is the answer I got, is it correct?
s = n(C – D)

Business and finance. Jose has savings accounts for each of his five children. They contain $215, $156, $318, $75, and $25. Find the median and the mean amount of money per account.

This is the answer I got, is it correct?

Median = 156

789/5 = 157.80

-4(2x – 3) = -8x + 5

This is the answer I got, is it correct?

x = 7/16

and just please help me with this one.

A = 1/2h (B + b) (for b) Area of trapezoid

I think my brain is having a meltdown!

Serious answers only, please~!

it is a negative
-4(2x – 3) = -8x + 5

and please look a this one too.

x(3) = 5

Answer 1

Your first two are correct - nice job!

The equation is off though - let's look at that one.

-4(2x – 3) = -8x + 5
-8x + 12 = -8x + 5
12 = 5

When you try to collect the x terms on one side, they actually cancel out and you end up with no variables. What you're left with is a nonsense statement - this means that there are no real solutions for this problem.

Finally, for your trapezoid, you want to solve for b. Do it just like you did your first problem. For this, make sure you take care of the area before the parentheses first:

A = 1/2h (B + b)
2A/h = B + b
b = 2A/h - B

Answer 2

Yes, s = n(C - D). The median/mean problem is also correct.
As to the third problem, are you sure you typed it correctly? After you multiply the -4 through, you have -8x + 12 = -8x + 5. Eventually you'd come to 7 = 0... Obviously this is not possible. If what you meant to type was 4(2x - 3) = -8x + 5, the correct answer is 17/16.
For the last one, b = 2A/h - B. Best of luck.

Answer 3

d=(c-s)/n To get rid of the branch of the "n", you need to multiply the two factors by skill of "n". This leaves you with: n(d)=((c-s)/(n))(n) This leaves you with: nd=c-s To get the s by skill of itself, you need to get rid of the "c". to do this, you SUBTRACT "c" from the two factors, with a view to cancel the "+s" out. nd=c-s -c -c This leaves you with: nd-c=s that's: s=nd-c stable luck! wish I helped! :)