document.write( "Question 642119: Could someone explain too me, how to solve this problem, it would be much appreicated.
\n" ); document.write( "A parabola with equation y = ax^2 + bx passes through the two points (-1,3) and (4,-2).
\n" ); document.write( "(a) Use algebra to find its equation.
\n" ); document.write( "Hint: Set up a system of two simultaneous equations. \r
\n" ); document.write( "\n" ); document.write( "and could you please explain the steps you go through to get the end result.
\n" ); document.write( "

Algebra.Com's Answer #403964 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
A parabola with equation \"y+=+ax%5E2+%2B+bx\" passes through the two points (\"-1\",\"3\") and (\"4\",\"-2\")\r
\n" ); document.write( "\n" ); document.write( "you need to find the three unknown coefficients \"a\" and \"b\"
\n" ); document.write( "Insert each of the \"2\" points and you will get \"2\" equations with \"2\" unknowns:\r
\n" ); document.write( "\n" ); document.write( "\"3+=+a%28-1%29%5E2+%2B+b%28-1%29.....1\"\r
\n" ); document.write( "\n" ); document.write( "\"-2+=+a%284%29%5E2+%2B+b%284%29.....2\"
\n" ); document.write( "_____________________solve this system by substitution\r
\n" ); document.write( "\n" ); document.write( "\"3+=+a%28-1%29%5E2+%2B+b%28-1%29\".....1....solve for \"a\"\r
\n" ); document.write( "\n" ); document.write( "\"3+=+a+-b\"\r
\n" ); document.write( "\n" ); document.write( "\"3+%2Bb=+a\" ..........................substitute in 2\r
\n" ); document.write( "\n" ); document.write( "\"-2+=+%283+%2Bb%29%284%29%5E2+%2B+b%284%29\".....2....solve for \"b\"\r
\n" ); document.write( "\n" ); document.write( "\"-2+=+%283+%2Bb%29%2A16+%2B+4b\"\r
\n" ); document.write( "\n" ); document.write( "\"-2+=+48+%2B16b+%2B+4b\"\r
\n" ); document.write( "\n" ); document.write( "\"-2+-+48+=20b\"\r
\n" ); document.write( "\n" ); document.write( "\"-50=20b\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%28-2.5=b%29\"\r
\n" ); document.write( "\n" ); document.write( "now find \"a\"\r
\n" ); document.write( "\n" ); document.write( "\"3+%2Bb=+a\"\r
\n" ); document.write( "\n" ); document.write( "\"3+-2.5=+a\"\r
\n" ); document.write( "\n" ); document.write( "\"highlight%280.5=+a%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=+ax%5E2+%2B+bx\"........plug in \"a\" and \"b\"\r
\n" ); document.write( "\n" ); document.write( "\"y+=0.5x%5E2+-2.5x\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+0.5x%5E2+-2.5x%29+\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );