A chemist needs 190 milliliters of a 47% solution but has only 25% and 63% solutions available. Find how many milliliters of each that should be mixed to get the desired solution.

Question

perl · Answer

If we assume that 
x = number of milliliters of 25% solution 
y = number of milliliters  of 63% solution

 x + y = 190 
.25x + .63y = 190 * .47

destinyyyy · Answer

Okay

destinyyyy · Answer

I match up the y's to cancel them out correct?

perl · Answer

yes, you can solve by substitution or elimination

destinyyyy · Answer

I got x=317.38 which cant be correct

perl · Answer

x + y = 190 
.25x + .63y = 190 * .47

multiply the second equation by 100. that will get rid of decimals. 

x+y=190
25x + 63y = 8930

destinyyyy · Answer

x=-230 then I plug this into x+y=190

perl · Answer

x should be positive

destinyyyy · Answer

Yes ... For x+y=190 times it all by -63 to cancel out the ys ... But then I get -38x=8740

perl · Answer

Did you get this?

-63x -63y = -11970
25x + 63y = 8930

perl · Answer

I multiplied first equation by -63

destinyyyy · Answer

-.- oh my gosh i left it as -190

perl · Answer

:D

destinyyyy · Answer

x=80 and y=110

destinyyyy · Answer

Thank you!