5. Solve using the quadratic formula:
x2 – 3x = 4x – 1
6. Solve using the quadratic formula:
x2 – 5x – 1 = -7
2007-06-11 17:34:04 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
5. Use the quadratic formula: x^2 - 3x = 4x - 1
Quad form: x = [-b +/- V`b^2 - 4ac] / 2a
First: set the equation to "0" - add 1 to both sides (when you move a term to the opposite side, always use the opposite sign).
x^2 - 3x + 1 = 4x - 1+1
x^2 - 3x + 1 = 4x (subtract 4x from both sides).
x^2 - 3x + 1 - 4x= 4x-4x
x^2 - 7x + 1 = 0
Sec: three terms...a = 1; b = -7; c =1 > substitute the terms with the corresponding variables.
x = [-(-7) +/- V`(-7)^2 - 4(1)(1)] / 2(1)
x = [ 7 +/- V`(-7)(-7) - 4(1)(1)] / 2
x = [ 7 +/- V`49 - 4(1)] / 2
x = [ 7 +/- V`49 - 4] / 2
x = [ 7 +/- V`45] / 2
x = [ 7 +/- V`3*3*5] / 2
x = [ 7 +/- 3 V`5] / 2
Third: there are 2 solutions...
x = [ 7 + 3 V`5] / 2 & [ 7 - 3 V`5] / 2
6. Solve using the quadratic formula:
x^2 - 5x - 1 = -7 (add 7 with both sides).
x^2 - 5x - 1+7 = -7+7
x^2 - 5x + 6 = 0 (follow the same format from #5)
2007-06-11 17:48:48 · answer #1 · answered by ♪♥Annie♥♪ 6 · 1⤊ 0⤋
bring everything to one side
x2 -7x +1 = 0
a=1 b=-7 c=1
.......
x2 - 5x + 8 = 0
a=1 b=-5 c=8
just plug in those values into the quadratic equation and you have found x!
2007-06-12 00:39:26 · answer #2 · answered by Jud R 3 · 0⤊ 1⤋
5. x^2 - 3x = 4x -1
x^2 - 7x +1 = 0
a = 1
b = -7
c = 1
-(-7) +-sqrt((-7)^2-4(1)(1)) / 2(1)
7 +-sqrt(45) /2
(7+-3sqrt5)/2
2007-06-12 00:56:05 · answer #3 · answered by latus rectum 1 · 0⤊ 0⤋
Someone is lazy. GET ALL TERMS ON ONE SIDE so they equal zero. COMBINE like terms. Then a= coefficent of the x^2 term, b= coefficient of the x term, and c= constant. Don't forget the signs!!
2007-06-12 00:39:23 · answer #4 · answered by cattbarf 7 · 0⤊ 0⤋
What the hell is the quadratic formula!?!?
2007-06-12 00:41:22 · answer #5 · answered by Anonymous · 0⤊ 2⤋