SOLUTION: Hi ok so here's my problem: How many ounces of a 15% acid solution and a 40% acid solution must be mixed together to produce 30 ounces of a 33 1/3 acid soltuion? I know how to d

Algebra ->  College  -> Linear Algebra -> SOLUTION: Hi ok so here's my problem: How many ounces of a 15% acid solution and a 40% acid solution must be mixed together to produce 30 ounces of a 33 1/3 acid soltuion? I know how to d      Log On


   



Question 692628: Hi ok so here's my problem: How many ounces of a 15% acid solution and a 40% acid solution must be mixed together to produce 30 ounces of a 33 1/3 acid soltuion?
I know how to do it once I have the equation.
The first equation I had was;
x+y=30
.15x+.40y=30(33 1/3) and then you use combination method but when I tried it I didn't get the right answer?
If you coudl just help me get the equation that would be great thanks so much!

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Note that +33.333+ in the problem is a percent
(1) +x+%2B+y+=+30+
(2) +.15x+%2B+.4y+=+30%2A.333+
(2) +15x+%2B+40y+=+1000+
Multiply both sides of (1) by +15+ and
subtract (1) from (2)
(2) +15x+%2B+40y+=+1000+
(1) +-15x+-+15y+=+-450+
+25y+=+550+
+y+=+22+
and
(1) +x+%2B+y+=+30+
(1) +x+%2B+22+=+30+
(1) +x+=+8+
-------------
check:
(2) +.15%2A8+%2B+.4%2A22+=+30%2A.333+
(2) +1.2+%2B+8.8+=+10+
(2) +10+=+10+
OK