<PRE><B>Question 184214</B>
Betty and Sue use a metal that is 17.3% copper to make jewelry.
 How many ounces of a 17% alloy must be mixed with a 18% alloy
 to form 80 ounces of the desired alloy?
:
Let x = amt of 18% alloy required
:
It states the total of the two alloys will be 80 oz, therefore:
(80-x) = amt of 17% alloy required
:
Write the decimal equiv equation:
:
.17(80-x) + .18x = .173(80)
:
13.6 - .17x + .18x = 13.84
:
-.17x + .18x = 13.84 - 13.6
:
.01x = .24
x = {{{.24/.01}}}
x = 24 oz of 18% copper 
and
80 - 24 = 56 oz of 17% copper
:
:
Check solution in original equation
.17(56) + .18(24) = .173(80)
9.52 + 4.32 = 13.84; confirms our solutions</PRE>