document.write( "Question 308383: how do i solve 12 x ² +19 x=21 by completing the square and using the formula a(x-h)²+k \n" ); document.write( "
Algebra.Com's Answer #220498 by CharlesG2(834)\"\" \"About 
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how do i solve 12 x ² +19 x=21 by completing the square and
\n" ); document.write( "using the formula a(x-h)²+k\r
\n" ); document.write( "\n" ); document.write( "a(x-h)^2 + k = a(x^2 - 2hx + h^2) + k = 0
\n" ); document.write( "12x^2 + 19x - 21 = 0
\n" ); document.write( "12(x^2 + (19/12)x - (21/12)) = 0
\n" ); document.write( "12(x^2 + (19/12)x + (19/24)^2 - (21/12)) = 12(19/24)^2
\n" ); document.write( "12(x + (19/24))^2 + 12(-21/12) = 12(19/24)^2
\n" ); document.write( "12(x + (19/24))^2 - 21 - 12(361/576) = 0
\n" ); document.write( "-21 - 12(361/576) = -21 - 4332/576 = -12096/576 - 4332/576 = -16428/576
\n" ); document.write( "-16428/576 = -1369/48 = -28 and ?/48
\n" ); document.write( "-28 * 48 = -1344
\n" ); document.write( "-1369/48 = -28 and 25/48 = approx. -28.52083
\n" ); document.write( "12(x + (19/24))^2 - 1369/48 = 0 [a(x-h)^2 + k = 0 form]
\n" ); document.write( "h = - 19/24 = approx. -0.79167
\n" ); document.write( "k = -1369/48 = approx. -28.52083
\n" ); document.write( "(h,k) is the vertex of this parabola which opens upward since a = positive 12
\n" ); document.write( "(x + (19/24))^2 = 1369/48 * 1/12
\n" ); document.write( "(x + (19/24))^2 = 1369/576
\n" ); document.write( "x + 19/24 = 37/24 OR x + 19/24 = -37/24
\n" ); document.write( "x = 18/24 = 3/4 OR x = -56/24 = -7/3
\n" ); document.write( "\"+graph%28+300%2C+300%2C+-5%2C+5%2C+-30%2C+10%2C+12x%5E2+%2B+19x+-+21%29+\"\r
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