document.write( "Question 91076: solve 8x-5+9x=17x-5. Describe the type of answer if applicable \n" ); document.write( "
Algebra.Com's Answer #66696 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! Given: \n" ); document.write( ". \n" ); document.write( "8x - 5 + 9x = 17x - 5 \n" ); document.write( ". \n" ); document.write( "Notice that on the left side you can combine the two terms that contain x. 8x + 9x equals 17x. \n" ); document.write( ". \n" ); document.write( "When you make that change the equation becomes: \n" ); document.write( ". \n" ); document.write( "17x - 5 = 17x - 5 \n" ); document.write( ". \n" ); document.write( "Notice that the left side of this equation is identical to the right side. Because of \n" ); document.write( "this reason, this type of equation is called an identity. Whatever value you wish to choose \n" ); document.write( "for x, the given equation will always be true. \n" ); document.write( ". \n" ); document.write( "For example, in the given equation if you substitute 10 for x the equation becomes: \n" ); document.write( ". \n" ); document.write( "8(10) - 5 + 9(10) = 17(10) - 5 \n" ); document.write( ". \n" ); document.write( "and this simplifies to: \n" ); document.write( ". \n" ); document.write( "80 - 5 + 90 = 170 - 5 \n" ); document.write( ". \n" ); document.write( "which further reduces to: \n" ); document.write( ". \n" ); document.write( "165 = 165 \n" ); document.write( ". \n" ); document.write( "Now try a different value for x. Suppose you choose x = 0. The equation becomes: \n" ); document.write( ". \n" ); document.write( "8(0) - 5 + 9(0) = 17(0) - 5 \n" ); document.write( ". \n" ); document.write( "and this reduces to: \n" ); document.write( ". \n" ); document.write( "-5 = -5 \n" ); document.write( ". \n" ); document.write( "Finally, let's choose x = -4. Substituting this value for x in the given equation \n" ); document.write( "gives: \n" ); document.write( ". \n" ); document.write( "8(-4) - 5 + 9(-4) = 17(-4) - 5 \n" ); document.write( ". \n" ); document.write( "Doing the multiplications results in: \n" ); document.write( ". \n" ); document.write( "-32 - 5 - 36 = -68 - 5 \n" ); document.write( ". \n" ); document.write( "and combining the terms on the left and right sides: \n" ); document.write( ". \n" ); document.write( "-73 = -73 \n" ); document.write( ". \n" ); document.write( "This should give you the idea of what an identity means. Our examples show that no matter \n" ); document.write( "what value we tried for x, both sides of the given equation were equal. \n" ); document.write( ". \n" ); document.write( "Hope this clarifies the problem for you. \n" ); document.write( " |