5x(2y-3)-(y+8)=13 I believe this is correct
ANSWER:
6_34/99
STEP:
So yes. When a decimal is repeating, you can take the repeating number (most likely a decimal) and put 99 under it. Since 99 cannot be solved, you put 99. So, 34/99. Though we are not finished. There is still the whole 6 number left. So, you do 6_34/99.
Proof:
10x=6.6...
-x=-0.6...
9x=6
x=6/9=1/3.
To find probability, you'd have to find the total number of marbles (5+3+6+6=20), and since there are 3 blue marbles, the probability of picking one is 3 out of 20, or 3/20
If that blue marble isn't replaced, there will then be 19 marbles, and 2 blue ones. So the probability of him picking another blue marble is 2/19
I am going to explain this using the substitution method, considering it appears to be the best in this situation.
We know (from the bottom equation) that y can equal 3x+20. Using this knowledge, we substitute the y in the top equation for 3x+20. Now, we have an equation that looks like this:
3x+20=x^2+2x
Now we need to move x to one side and then do some radicals (square roots).
Subtract the 2x on the right (since it is smaller, negatives = NONONO), which will give you
x+20=x^2
Now, we take the square root of both sides to get
rad(x+20)=x
Now we have to simplify. 20 doesn't have a square root, but 4 goes into 20, and 4 has a square root of 2. This now becomes
2rad(x+5)
This doesn't simplify any further... we have a problem... no way to isolate x as far as my knowledge goes... Sorry, can't help you any further than that, but another person or your teacher might be able to. R.I.P...