This is an Algebra Two Honors question:

A jeweler has 12 grams of an 80% gold alloy that she wants to strengthen to 92.5%. Write the rational function, P(x), which is the percent of gold in the alloy by mass where x is the number of grams of gold added.

A) Write the rational function P(x). Use these three expressions to write your rational expression: (12+x), 100x, and 12(80).

B) Graph the function for the domain 0
C) Use your function an find out how much gold the jeweler must add to create a 92.5% alloy.

I'm back so
80% of 12=9.6 grams=gold so

so she wants to add to the alloy to make the gold 92.5% gold so

I'm not sure how to do A or B but I think the answer to B is 2.4 grams

C. so the jewler has 2.4 grams of alloy
we must find out when 2.4=7.5%, what is 100%
so if 2.4=.075x then 24=0.75x then 32 grams=100 %
so 32-2.4=29.6 grams
29.6/32=0.925 or 92.5%

this is not the legit way to do it

Answer Link