John took money out of his account. He bought a radio for $108. He used 5/9 of what was left for presents and then put 5/6 of the leftover into another account and gave away the remaining $80 to charity. How much did he start with?
help
found you
Ok, let's denote $ he start with as X
ok
Since he bought the radio he has less money. $108 less money so x-108 make sense so far?
ok
let's go to next part of the question. " He used 5/9 of what was left for presents" The leftover is x-108. So 5/9 of left over is 5/9(x-108 ) good?
good
So money left after buying the radio is( x-180) and he spend 5/9 of it. So we subtract. \[(x-180)-\frac{5}{9}(x-180)\] We can factor to make it look neat \[(x-180)(1-\frac{5}{9})\] \[(x-180)(\frac{4}{9})\] So this is how much money he has left after he bought the radio,use money for the present. Does this make sense?
no--back up, to the (x-108) -5/9(x-108)
(x-108) is how much he has left after buying the radio. He used 5/9 of left over to buy present. So we do (x-108) -5/9(x-108) to get new leftover
Would that be -5/9x + 60
I see you multiplied it ,yes
5/9 * 108
that's correct so subtract -5/9x + 60 from (x-108) to get new left over x-108-5/9x+60
I factored it, instead of multiplying out
clear?
what next
"then put 5/6 of the leftover into another account" \[ (x-108-\frac{5}{9}x+60) -\frac{5}{6}(x-108-\frac{5}{9}x+60)\]
Any question?
whereis the 80 that is left
I am not there yet
ok sorry
But so far so good right?
ok
" gave away the remaining $80 to charity" This part tell us that he has 80 remaining after buying radio,buying present, putting money in another account. So we may set the previous equation equals to 80 \[(x−108−\frac{5}{9}x+60)−\frac{5}{6}(x−108−\frac{5}{9}x+60)=80\] Now you are all set to solve for x, just some algebra
don't lave me now__I have stressed over this thing enough
You solve for x; I will too then we will compare result
* Tip First add like term inside the parenthesis before distributing
It isn't working!!
what do you mean?
it is supposed to come out to 1188 and I'm not getting it.
That's what I got
did you do the sectios separate or together
I do not have a math gene in my body
\[\left(x-108-\frac{5}{9}x+60\right)-\frac{5}{6}\left(x-108-\frac{5}{9}x+60\right)\text{==}80\] Add like term inside the parethesis \[(-48+\frac{4 x}{9})-\frac{5}{6}(-48+\frac{4 x}{9})==80\] \[(-48+\frac{4 x}{9}+40-\frac{10 x}{27})==80\] \[-8+\frac{2 x}{27}=80\] \[\frac{2 x}{27}=88\] \[{2 x}=2376\] \[{2 x}=2376\] X=1128
2x=2376 x=1188
This I understand___I just had to see my error__it was the algebra--I did not combine the x's properly.
You have lifted a weight off my shoulders.
Yeah, be careful with algebra, use calculator if you are allowed
I will--exam is tomorrow
What grade?
It is a college course for elementary education. I need it to graduate next month.
It is online and I don't get much feedback.
Good luck on the test tomorrow.
Thank you again. good nite
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