document.write( "Question 1060021: The length of a rectangle is 3 inches longer than it is wide. If the area is 70 square inches, what are the dimensions of the rectangle? \n" ); document.write( "
Algebra.Com's Answer #675057 by acw1213(28)![]() ![]() You can put this solution on YOUR website! We need to write a system of equations here.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "One equation will include the formula for the area/ \n" ); document.write( "The formula for the area of a rectangle is \n" ); document.write( "Lw = a\r \n" ); document.write( "\n" ); document.write( "where\r \n" ); document.write( "\n" ); document.write( "L = length \n" ); document.write( "W = width \n" ); document.write( "a = area\r \n" ); document.write( "\n" ); document.write( "Plug in the area where it is necessary.\r \n" ); document.write( "\n" ); document.write( "Lw = 70\r \n" ); document.write( "\n" ); document.write( "One equation is finished!\r \n" ); document.write( "\n" ); document.write( "The next equation will be the situation described in your response.\r \n" ); document.write( "\n" ); document.write( "The length is 3 inches added to the width.\r \n" ); document.write( "\n" ); document.write( "In an equation, it is\r \n" ); document.write( "\n" ); document.write( "3 + w = L\r \n" ); document.write( "\n" ); document.write( "Now use your systems,\r \n" ); document.write( "\n" ); document.write( "3 + w = L \n" ); document.write( "Lw = 70\r \n" ); document.write( "\n" ); document.write( "to solve for the length and width.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I'm going to solve using substitution.\r \n" ); document.write( "\n" ); document.write( "Substitute 3 + w in for \"L\" in the second equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(3 + w)(w)=70\r \n" ); document.write( "\n" ); document.write( "Distribute.\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now we have a quadratic equation on our hands. Let's get this into standard form.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Subtract 70 from both sides.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We cannot factor this, so solve using the quadratic formula.\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a = 3 \n" ); document.write( "b = 1 \n" ); document.write( "c = -70\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Plug in and solve for w.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Simplify. Please view my steps.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I squared 1 and multiplied -4 by 3, and then by -70. \n" ); document.write( "I multiplied 2 times 3. \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I added one to 840.\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I found the square root of 841, which is 29.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now, we need to solve for \"w\". -1 can be ADDED or SUBTRACTED from 29, so we need to solve for both\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Addition:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-1 + 29 is 28. \n" ); document.write( "28 / 6 can be simplified to 14/3.\r \n" ); document.write( "\n" ); document.write( "w = 14/3\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Subtraction:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-1 - 29 is -30. \n" ); document.write( "-30 / 6 is -5.\r \n" ); document.write( "\n" ); document.write( "w = -5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now we have a problem. w can equal -5 or 14/3. \n" ); document.write( "-5 is the more logical answer since 14/3 will turn out to be a repeating decimal.\r \n" ); document.write( "\n" ); document.write( "Our width is -5.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Don't worry, our system is not old news yet! \n" ); document.write( "Let's return to it.\r \n" ); document.write( "\n" ); document.write( "Lw = 70 \n" ); document.write( "w + 3 = L \n" ); document.write( "Let's plug in -5 for \"w\" in the second equation and solve for \"L\".\r \n" ); document.write( "\n" ); document.write( "-5 + 3 = L\r \n" ); document.write( "\n" ); document.write( "-5 + 3 is -2.\r \n" ); document.write( "\n" ); document.write( "-2 = L\r \n" ); document.write( "\n" ); document.write( "YAY! We are finished! \n" ); document.write( "Our width is -5 and our length is -2. These are our DIMENSIONS. \n" ); document.write( " |