document.write( "Question 136259: Solve the followings : \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "1)A semiconductor manufacturer seeks to maximize its profits. Testing indicates that they can produce 100,000 chips per week at a cost of $40 per chip, and sell them for $65 per chip. They also find that they can produce 125,000 chips per week at a cost of $35 per chip, and sell them for $63 per chip. How much profit can they expect to earn if they produce 130,000 chips per week?\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "2)Find the area of a rectangle if three of its corners are (-0.1,-3.4), (-7.9,-3.4), and (-0.1,6.8).
\n" ); document.write( "

Algebra.Com's Answer #99836 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
I can plot this data on a straight line, otherwise called
\n" ); document.write( "a linear plot. The problem doesn't say I can do this, but
\n" ); document.write( "it doesn't exclude it either, and it's the simplest thing
\n" ); document.write( "to do. I'm going to plot both cost/chip
\n" ); document.write( "and price/chip vs chips produced/wk
\n" ); document.write( "In plotting, the vertical axis is always the data that
\n" ); document.write( "RESULTS when changes are made on the x-axis.
\n" ); document.write( "So, the y-axis is cost/chip and price/chip. The x-axis is chips
\n" ); document.write( "produced/wk. I can plot 2 points for cost and 2 points for price
\n" ); document.write( "which gives me 2 straight lines.
\n" ); document.write( "---------------
\n" ); document.write( "For cost/chip:
\n" ); document.write( "First point:
\n" ); document.write( "\"x+=+100000\"
\n" ); document.write( "\"y+=+40\"
\n" ); document.write( "Second point:
\n" ); document.write( "\"x+=+125000\"
\n" ); document.write( "\"y+=+35\"
\n" ); document.write( "---------------
\n" ); document.write( "For price/chip:
\n" ); document.write( "first point:
\n" ); document.write( "\"x+=+100000\"
\n" ); document.write( "\"y+=+65\"
\n" ); document.write( "Second point:
\n" ); document.write( "\"x+=+125000\"
\n" ); document.write( "\"y+=+63\"
\n" ); document.write( "---------------
\n" ); document.write( "I use the formula
\n" ); document.write( "
\n" ); document.write( "I'll scale the x-axis so 1 unit = 10000 units
\n" ); document.write( "----------------
\n" ); document.write( "For cost/chip vs production/wk
\n" ); document.write( "\"%2835+-+40%29+%2F+%2812.5+-+10%29+=+%28y+-+40%29+%2F+%28x+-+10%29\"
\n" ); document.write( "\"%28-5%29%2F2.5+=+%28y+-+40%29+%2F+%28x+-+10%29\"
\n" ); document.write( "\"%28-2%29%2A%28x+-+10%29+=+y+-+40\"
\n" ); document.write( "\"y+=+-2x+%2B+60\"
\n" ); document.write( "For price/chip vs production/wk
\n" ); document.write( "\"%2863+-+65%29+%2F+%2812.5+-+10%29+=+%28y+-+65%29+%2F+%28x+-+10%29\"
\n" ); document.write( "\"%28-2%29+%2F+2.5+=+%28y+-+65%29+%2F+%28x+-+10%29\"
\n" ); document.write( "\"%28-.8%29%2A%28x+-+10%29+=+y+-+65\"
\n" ); document.write( "\"y+=+-.8x+%2B+73\"
\n" ); document.write( "One way to check these lines is to plot them
\n" ); document.write( "\"+graph%28+600%2C+600%2C+-1%2C+20%2C+-5%2C+85%2C+-2x+%2B+60%2C+-.8x+%2B+73%29+\"
\n" ); document.write( "At 13,000 chips/wk (13 on the graph), the profit is the difference
\n" ); document.write( "in the y-coordinates (price - cost)
\n" ); document.write( "cost:
\n" ); document.write( "\"y+=+-2x+%2B+60\"
\n" ); document.write( "\"y+=+-2%2A13+%2B+60\"
\n" ); document.write( "\"y+=+34\"
\n" ); document.write( "price:
\n" ); document.write( "\"y+=+-.8x+%2B+73\"
\n" ); document.write( "\"y+=+-.8%2A13+%2B+73\"
\n" ); document.write( "\"y+=+62.6\"
\n" ); document.write( "price - cost = \"62.6+-+34+=+28.6\"
\n" ); document.write( "The profit at 130,000 chips/wk is $28.60 /chip
\n" ); document.write( "
\n" );