SOLUTION: I do not understand how to turn these in to linear equations? I can't figure out what to put where for an equation that will give me the answer I need. How much 90 percent vineg

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: I do not understand how to turn these in to linear equations? I can't figure out what to put where for an equation that will give me the answer I need. How much 90 percent vineg      Log On


   



Question 344495: I do not understand how to turn these in to linear equations? I can't figure out what to put where for an equation that will give me the answer I need.
How much 90 percent vinegar do you have to add to a gallon of 5 percent vinegar to get 20 percent vinegar?
________ gallons.
and
You can paint a certain room in 9 hours. Your brother can do it in 8 hours. How long does it take the two of you working together?
_____ hours.

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
How much 90 percent vinegar do you have to add to a gallon of 5 percent vinegar to get 20 percent vinegar?
You have 1 gallon of 5%
You need to add x gallons of 90%
The result will be (x+1) gallons of 20%
1%2A0.05+%2B+x+%2A0.9+=+%28x%2B1%29%2A0.2
0.05+%2B+0.9x+=+0.2x+%2B+0.2
0.7x+=+0.15
x+=+0.15%2F0.7 gallons of 90%
x+=+0.214 gallons
Make sense?

You can paint a certain room in 9 hours. Your brother can do it in 8 hours. How long does it take the two of you working together?
He can do you cna do 1/9 of the job in an hour. He can d0 1/8
Together you can do 1%2F9+%2B+1%2F8+=+8%2F72+%2B+9%2F72+=+17%2F72 of the job in an hour
x+%2A+17%2F72+=+1
x+=+72%2F17+=+4.235 hours