![\"\"](\"/images/stars/stars-13.gif\")
You can put this solution on YOUR website!
x = y+9
\n" ); document.write( "x × y = 70 substitute for x:
\n" ); document.write( "(y+9) × y = 70 now distribute the y (distributive properties of multiplication)
\n" ); document.write( "y^2+9y = 70
\n" ); document.write( "The coefficient of y is 9. Divide 9 by 2 and square it, then add to both sides of the equation:
\n" ); document.write( "y^2+9y+(9/2)^2 = 70+(9/2)^2
\n" ); document.write( "y^2+9y+81/4 = 70+81/4 solve the addition on the right: 70*4+81 = 361/4
\n" ); document.write( "y^2+9y+81/4 = 361/4 factor the left side. We have perfect squares so we can do it this way:
\n" ); document.write( "(y+9/2)^2 = 361/4 take the square root, both sides:
\n" ); document.write( "y+9/2 = 19/2 or y+9/2 = -19/2
\n" ); document.write( "y = 10/2 or y = -28/2
\n" ); document.write( "y = 5 or y = -14
\n" ); document.write( "---------------------------
\n" ); document.write( "Let's see which one's your answer, we'll start with the 5:
\n" ); document.write( "5+9 = 14 and 5*14 = 70 so there you have it, 5 is your answer\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "