document.write( "Question 184247: 114. Surface area of a cube. The formula A =6V^2/3 gives
\n" );
document.write( "the surface area of a cube in terms of its volume V. What is the volume of a cube with surface area 12 square feet? \r
\n" );
document.write( "\n" );
document.write( "94. Find all real or imaginary solutions to each equation.
\n" );
document.write( "49x^2+9=42x \r
\n" );
document.write( "\n" );
document.write( "98. x-1/x+2= 2x-3/x+4 \r
\n" );
document.write( "
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "110. Winston works faster. Winston can mow his dad’s lawn in 1 hour less than it takes his brother Willie. If they take 2 hours to mow it when working together, then how long would it take Winston working alone? \r
\n" );
document.write( "\n" );
document.write( "114. Maximizing profit. The total profit (in dollars) for sales of x rowing machines is given by P(x)=-0+2x^2+300x-200 . What is the profit if 500 are sold? For what value of x will the profit be at a maximum? \r
\n" );
document.write( "
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( " \n" );
document.write( "
Algebra.Com's Answer #138385 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! 114. Surface area of a cube. The formula A =6V^2/3 gives the surface area of \n" ); document.write( " a cube in terms of its volume V. \n" ); document.write( "What is the volume of a cube with surface area 12 square feet? \n" ); document.write( "write it: \n" ); document.write( " \n" ); document.write( "divide both sides by \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "Cube both sides and you have \n" ); document.write( "V^2 = 8 \n" ); document.write( "V = \n" ); document.write( "v = 2.828 cu/ft \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "94. Find all real or imaginary solutions to each equation. \n" ); document.write( "49x^2 + 9 = 42x \n" ); document.write( "49x^2 - 42x + 9 = 0 \n" ); document.write( "(7x-3)(7x-3) = 0 \n" ); document.write( "7x = 3 \n" ); document.write( "x = \n" ); document.write( ": \n" ); document.write( "98. \n" ); document.write( "Cross multiply \n" ); document.write( "(x-1)(x+4) = (x+2)(2x-3) \n" ); document.write( "FOIL \n" ); document.write( "x^2 + 3x - 4 = 2x^2 + x - 6 \n" ); document.write( "combine on the right \n" ); document.write( "0 = 2x^2 - x^2 + x - 3x - 6 + 4 \n" ); document.write( " x^2 - 2x - 2 = 0 \n" ); document.write( "Solve this using the quadratic formula: a=1; b=-2; c=-2 \n" ); document.write( "You should get: x = 2.732 and x = -.732 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "110. Winston works faster. Winston can mow his dad’s lawn in 1 hour less \n" ); document.write( " than it takes his brother Willie. If they take 2 hours to mow it when \n" ); document.write( " working together, then how long would it take Winston working alone? \n" ); document.write( ": \n" ); document.write( "let x = W's mowing time working alone \n" ); document.write( "then \n" ); document.write( "(x+1) = brother's time working alone \n" ); document.write( ": \n" ); document.write( "Let the completed job = 1 \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( "Multiply eq by x(x+1), results \n" ); document.write( "2(x+1) + 2x = x(x+1) \n" ); document.write( "2x + 2 + 2x = x^2 + x \n" ); document.write( "4x + 2 = x^2 + x \n" ); document.write( "0 = x^2 + x - 4x - 2 \n" ); document.write( "x^2 - 3x - 2 = 0; a quadratic equation \n" ); document.write( "Use the quadratic formula to solve this a=1; b=-3; c=-2 \n" ); document.write( "Positive solution: x=3.56 hrs W working alone \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "114. Maximizing profit. The total profit (in dollars) for sales of x rowing machines is given by P(x)=-0+2x^2+300x-200 . What is the profit if 500 are sold? \n" ); document.write( ": \n" ); document.write( "Assume you mean \n" ); document.write( " P(x)=-.2x^2+300x-200 \n" ); document.write( "substitute 500 for x \n" ); document.write( " P(x)=-.2(500^2) + 300(500) - 200 \n" ); document.write( " P(x)=-.2(250000) + 150000 - 200 \n" ); document.write( " P(x)=-50000 + 150000 - 200 \n" ); document.write( " P(x)= $99,800 profit \n" ); document.write( ": \n" ); document.write( "For what value of x will the profit be at a maximum? \n" ); document.write( "Use the axis of symmetry formula: x = -b/(2a); in this eq: a=-.2; b=300 \n" ); document.write( "x = \n" ); document.write( "x = \n" ); document.write( "x = 750 unit for max profit \n" ); document.write( " |