Ok this is the problem x^2-10X+18=0 .
As an answer i got 10(+)(-)2sqrt7 /2 = 5(+)(-)2sqrt7.
Is my answer correct. If not can someone help. THanks
2007-09-26 08:53:47 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
a = 1
b = -10
c = 18
x = [-b +- sqrt (b^2 - 4ac)] / 2a
= [10 +- sqrt (-10^2 - 4*1*18)] / 2(1)
= [10 +- sqrt (100 - 72)] / 2
= [10 +- sqrt 28] / 2
= [10 +- 2sqrt 7] / 2
= (10/2) +- (2sqrt7 / 2)
= 5 +- sqrt 7
So, your first answer is right, but you messed up when you simplified it. (You forgot to divide the 2sqrt 7 by 2.)
2007-09-26 09:02:30 · answer #1 · answered by Mathematica 7 · 1⤊ 0⤋
the right answer is ((10+-2sqrt(7))/2=5+-sqrt(7)
2007-09-26 15:59:23 · answer #2 · answered by santmann2002 7 · 0⤊ 0⤋
Yup. 5 +/- sqrt(7)
Good job.
2007-09-26 15:57:34 · answer #3 · answered by PMP 5 · 0⤊ 0⤋