(polynomials)
I just want to check if i got the right answer
x^2+3x-18x-40=0
ty
2007-12-02 23:28:46 · 5 answers · asked by xMwahahahahahahax 3 in Science & Mathematics ➔ Mathematics
[01]
x^2+3x-18x-40=0
x^2-15x-40=0
comparing this with the standard quadrativ equationax^2+bx+c=0.we get
a=1, b=-15 and c= -40
x={15+-sqrt(15^2-4*(-40)(1)}/2
=(15+-sqrt(225+160)/2
=(15+-sqrt385)/2
Therfore x=(15+-sqrt385)/2 ans.
2007-12-02 23:42:23 · answer #1 · answered by alpha 7 · 1⤊ 4⤋
0 it is 0
2007-12-02 23:30:50 · answer #2 · answered by Z37!W (is upside down) 2 · 0⤊ 1⤋
x^2 - 15x -40 = 0
nope
won;t happen easily
to have both 2nd and third as a negative -
one of factors must be a positive
and the difference between them must be 15
not 8 and 5 nor 2 and 20
sorry
2007-12-02 23:33:48 · answer #3 · answered by tom4bucs 7 · 0⤊ 1⤋
x² - 15x - 40 = 0
x = [15 ± √(225 + 160) ] / 2
x = [15 ± √(385) ] / 2
x = [15 ± 5√(15) ] / 2
2007-12-03 00:20:16 · answer #4 · answered by Como 7 · 2⤊ 1⤋
it simplifies to:
x^2 - 15x - 40 = 0
b^2 - 4ac = 225 + 160 = 385
X1 = (-b - sqrt(385))/2a = (15 - sqrt(385))/2
X2 = (-b + sqrt(385))/2a = (15 - sqrt(385))/2
2007-12-02 23:36:56 · answer #5 · answered by Anonymous · 1⤊ 1⤋