document.write( "Question 211912: How do you figure out this problem: -5x(2x-1)=3(x+4) \n" ); document.write( "
Algebra.Com's Answer #160094 by drj(1380)![]() ![]() You can put this solution on YOUR website! How do you figure out this problem: -5x(2x-1)=3(x+4) \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 1. Multiply everything out on both sides of the equation. After we mess around with the equation, we will get a quadratic equation. Here it goes:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " -5x(2x-1)=3(x+4) will yield: -10x^2+5x=3x+12.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 2. Now let's put everything on the right side so that the left side is zero. I like a positive number for the x^2 term. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " Step 2a. Add 10x^2 to both sides of equation in Step 1: \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " 10x^2-10x^2+5x=10x^2+3x+12\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: The 10x^2 terms cancel out on the left side.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " Step 2b. Simplify equation in step 2a. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " 5x=10x^2+3x+12\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 3. Subtract 5x both sides of equation in Step 2b to make left side =0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " 5x-5x=10x^2+3x-12-5x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note: Collect like terms and simplify 3x-5x=-2x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " Step 3a. Simplify to yield our final equation \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " 0=10x^2-2x-12 OR 10x^2-2x-12=0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 4. Now we have a quadratic equation in step 3a.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "where a=10, b=-2, and c=-12.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Step 5. Substitute a, b, and c in the formula. The steps are shown below:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Note when the quadratic equation is a parabola when the values of x are real numbers. See graph where it intersects the x-axis. This is when y=0, hence our quadratic equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "For Step-By-Step Videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra \r \n" ); document.write( "\n" ); document.write( " \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |