A chemist at a university needs to mix a 25% ethanol solution with a 40%ethanol solution to obtain 120mL of a 30% ethanol solution. How much of each kind is needed?
okay yeah, the two equations i got out of this was
yeah? no objections??? okay.......
yeah so i times the bottom equation by (-25) and that cancelled out the A's so i was left with
so i divided that out and got B=740...
i plugged that into the original equation and got A=(-704)
(-704)mL of 25% ethanol solution and 740 mL of 40% ethanol solution...
THAT CANT BE RIGHT! A NEGATIVE AMOUNT OF SOLUTION?
can someone please please please help me figure out what i did wrong?