Answer:
3-6
Step-by-step explanation:
because the distributive property
<span>Equation:
silver + silver = silver
0.45x + 0.60(40-x) = 0.48*40
----------------
45x + 60*40 - 60x = 48*40
--------
-15x = -12*40
x = (4/5)40
x = 32 lbs (amt of 45% slloy needed)
40-x = 8 lbs (amt of 60% alloy needed)</span>
Please see the answer here
http://www.wolframalpha.com/input/?i=y%5E-1%20dy%20%2Bye%5E%28cosx%29%20sinxdx%3D0