document.write( "Question 177853: Solve by completing the square. Show your work.[please]\r
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\n" ); document.write( "\n" ); document.write( "29. 2x2 - 6x + 1 = 0\r
\n" ); document.write( "\n" ); document.write( " 30. -x2 - 8x + 5 = 0\r
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\n" ); document.write( "\n" ); document.write( "31. 9x2 - 18x - 1 = 0\r
\n" ); document.write( "\n" ); document.write( " 32. -4x2 + 8x - 3 = 0
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Algebra.Com's Answer #132891 by gonzo(654)\"\" \"About 
You can put this solution on YOUR website!
equation # 29 is: ******************************************************
\n" ); document.write( "\"2%2Ax%5E2+-+6%2Ax+%2B+1+=+0\"
\n" ); document.write( "standard form of the equation is:
\n" ); document.write( "ax^2 + bx + c = 0
\n" ); document.write( "this is already in standard form.
\n" ); document.write( "a term = 2
\n" ); document.write( "b term = (-6)
\n" ); document.write( "c term = 1
\n" ); document.write( "---
\n" ); document.write( "first you move the constant to the right side of the equation by subtracting 1 from both sides of the equation to get :
\n" ); document.write( "\"2%2Ax%5E2+-+6%2Ax+=+-1\"
\n" ); document.write( "---
\n" ); document.write( "you then divide both sides of the equation by 2 to get:
\n" ); document.write( "\"x%5E2+-+3%2Ax+=+%28-1%2F2%29\"
\n" ); document.write( "---
\n" ); document.write( "you then take half of 3 and factor the left side of the equation to get:
\n" ); document.write( "\"%28x+-+%283%2F2%29%29%5E2+-+%283%2F2%29%5E2+=+%28-%281%2F2%29%29\"
\n" ); document.write( "this takes a little explaining.
\n" ); document.write( "start of explanation.
\n" ); document.write( "here's an example (not anything to do with this problem because the numbers are changed to make it simple).
\n" ); document.write( "take \"x%5E2+%2B+2x\".
\n" ); document.write( "if you take half the 2 and make this equal to \"%28x%2B1%29%5E2\", the answer will be:
\n" ); document.write( "\"x%5E2+%2B+2x+%2B+%281%29%5E2\"
\n" ); document.write( "that \"%281%29%5E2\" is extra, so you have to subtract it to keep the original equality intact.
\n" ); document.write( "you get:
\n" ); document.write( "\"%28x%2B1%29%5E2+-+1+=+%28x%5E2+%2B+2x+%2B+1%29-+1+=+x%5E2+%2B+2x\" which is what you started off with.
\n" ); document.write( "this is exactly what we did above:
\n" ); document.write( "we took \"x%5E2+-+3%2Ax\" and factored it to get:
\n" ); document.write( "\"%28x-3%2F2%29%5E2+-+%283%2F2%29%5E2\"
\n" ); document.write( "if you do the multiplication, you will see that:
\n" ); document.write( "
\n" ); document.write( "end of explanation.
\n" ); document.write( "---
\n" ); document.write( "you then add the (3/2)^2 term to both sides of the equation to get:
\n" ); document.write( "\"%28x+-+%283%2F2%29%29%5E2+=+%28-%281%2F2%29%29+%2B+%283%2F2%29%5E2\"
\n" ); document.write( "---
\n" ); document.write( "you then take the square root of both sides of the equation to get:
\n" ); document.write( "\"x+-+%283%2F2%29\" = +/- \"sqrt%28%28-1%2F2%29+%2B+%283%2F2%29%5E2%29\"
\n" ); document.write( "---
\n" ); document.write( "you then add ((3/2)) to both sides of the equation to get:
\n" ); document.write( "x = +/- \"%28sqrt%28%28-1%2F2%29+%2B+%283%2F2%29%5E2%29%29+%2B+%283%2F2%29\"
\n" ); document.write( "---
\n" ); document.write( "after doing the math (i used a calculator), you will get:
\n" ); document.write( "x = 2.8228...
\n" ); document.write( "or
\n" ); document.write( "x = .1771...
\n" ); document.write( "---
\n" ); document.write( "to prove these values are correct, substitute them in the original equation (again i used the calculator with the full rather than the truncated values)
\n" ); document.write( "i took the original equation of 2x^2 - 6x + 1 = 0
\n" ); document.write( "and substituted these values to get:
\n" ); document.write( "0 = 0 both times proving both values are good.
\n" ); document.write( "---
\n" ); document.write( "equation number 32 is: ***********************************************
\n" ); document.write( "\"-4%2Ax%5E2+%2B+8%2Ax+-+3+=+0\"
\n" ); document.write( "standard form of the equation is:
\n" ); document.write( "ax^2 + bx + c = 0
\n" ); document.write( "this is already in standard form.
\n" ); document.write( "a term = -4
\n" ); document.write( "b term = 8
\n" ); document.write( "c term = -3
\n" ); document.write( "---
\n" ); document.write( "first you move the constant to the right side of the equation by adding 3 to both sides of the equation to get :
\n" ); document.write( "\"-4%2Ax%5E2+%2B+8%2Ax+=+3\"
\n" ); document.write( "---
\n" ); document.write( "you then divide both sides of the equation by (-4) to get:
\n" ); document.write( "\"x%5E2+-+2%2Ax+=+-3%2F4\"
\n" ); document.write( "---
\n" ); document.write( "you then take half of 2 and factor the left side of the equation to get:
\n" ); document.write( "\"%28x+-+1%29%5E2+-+%281%29%5E2+=+-3%2F4%29\"
\n" ); document.write( "---
\n" ); document.write( "you then add the (1)^2 term to both sides of the equation to get:
\n" ); document.write( "\"%28x-1%29%5E2+=+%28-3%2F4%29+%2B+1\"
\n" ); document.write( "---
\n" ); document.write( "you then take the square root of both sides of the equation to get:
\n" ); document.write( "\"x-1\" = +/- \"sqrt%28%28-3%2F4%29+%2B+1%29\"
\n" ); document.write( "---
\n" ); document.write( "you then add 1 to both sides of the equation to get:
\n" ); document.write( "x = +/- \"%28sqrt%28%28-3%2F4%29+%2B+1%29%29+%2B+1\"
\n" ); document.write( "---
\n" ); document.write( "after doing the math (i used a calculator), you will get:
\n" ); document.write( "x = 1.5
\n" ); document.write( "or
\n" ); document.write( "x = .5
\n" ); document.write( "---
\n" ); document.write( "to prove these values are correct, substitute them in the original equation (again i used the calculator with the full rather than the truncated values)
\n" ); document.write( "i took the original equation of -4x^2 + 8x - 3 = 0
\n" ); document.write( "and substituted these values to get:
\n" ); document.write( "0 = 0 both times proving both values are good.
\n" ); document.write( "---
\n" ); document.write( "i will do number 30 next and i will leave number 31 for you to do.
\n" ); document.write( "if you follow the steps and understand what is going on, you should be able to complete it.
\n" ); document.write( "---
\n" ); document.write( "equation number 30 is: **************************************************
\n" ); document.write( "\"-x%5E2+-+8%2Ax+%2B+5+=+0\"
\n" ); document.write( "standard form of the equation is:
\n" ); document.write( "ax^2 + bx + c = 0
\n" ); document.write( "this is already in standard form.
\n" ); document.write( "a term is -1.
\n" ); document.write( "b term is -8.
\n" ); document.write( "c term is 5
\n" ); document.write( "---
\n" ); document.write( "first you move the constant to the right side of the equation by subtracting 5 from both sides of the equation to get :
\n" ); document.write( "\"-x%5E2+-+8%2Ax+=+-5\"
\n" ); document.write( "---
\n" ); document.write( "you then divide both sides of the equation by -1 to get:
\n" ); document.write( "\"x%5E2+%2B+8%2Ax+=+5\"
\n" ); document.write( "---
\n" ); document.write( "you then take half of 8 and factor the left side of the equation to get:
\n" ); document.write( "\"%28x+%2B+4%29%5E2+-+4%5E2+=+5\"
\n" ); document.write( "---
\n" ); document.write( "you then add the 4^2 term to both sides of the equation to get:
\n" ); document.write( "\"%28x%2B4%29%5E2+=+5+%2B+4%5E2\"
\n" ); document.write( "---
\n" ); document.write( "you then take the square root of both sides of the equation to get:
\n" ); document.write( "\"x%2B4+=+sqrt%285+%2B+4%5E2%29\"
\n" ); document.write( "---
\n" ); document.write( "you then subtract 4 from both sides of the equation to get:
\n" ); document.write( "x = +/- \"sqrt%285+%2B+4%5E2%29-4\"
\n" ); document.write( "---
\n" ); document.write( "after doing the math (i used a calculator), you will get:
\n" ); document.write( "x = .5828...
\n" ); document.write( "or
\n" ); document.write( "x = =-8.5825...
\n" ); document.write( "---
\n" ); document.write( "to prove these values are correct, substitute them in the original equation (again i used the calculator with the full rather than the truncated values)
\n" ); document.write( "i took the original equation of -x^2 - 8x + 5 = 0
\n" ); document.write( "and substituted these values to get:
\n" ); document.write( "0 = 0 both times proving both values are good.
\n" ); document.write( "---
\n" ); document.write( "by now, you should be able to do number 31 by yourself.
\n" ); document.write( "let me know if you are having problems.
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