solve by using quadratic formula. 6x^2 - 5x = 8
show all steps!! thanks!!
2007-11-30 17:44:32 · 4 answers · asked by Aliyah 1 in Science & Mathematics ➔ Mathematics
6x² - 5x - 8 = 0
x = [ 5 ± √(25 + 192) ] / 12
x = [ 5 ± √ (217) ] / 12
This is exact answer.
Approximate answer is obtained by carrying out the arithmetic calculation
x = 1.64, x = - 0.81
2007-11-30 22:06:54 · answer #1 · answered by Como 7 · 5⤊ 1⤋
this sum can not be solved by quadratic formula one of the numbers are incorrect:
6x^2-5x=8
6x^2-5x-8=0
6x^2-___-8=0 (there is noway how -5x can be divided to satisfy
both 6x^2 and -8)
2007-11-30 18:13:11 · answer #2 · answered by Abhi007 2 · 0⤊ 0⤋
If your equation is
ax^2+bx+c = 0 then
roots of this equation are
[-b +or- sqrt(b^2-4ac)] / 2a
Here equation is
6x^2-5x-8=0
On comparison
a=6, b= -5, c= -8
discriminant delta = sqrt(b^2-4ac) = sqrt (25-(4*6*(-8)))
= sqrt(217) = 14.73
Roots are
[-b +or- sqrt(b^2-4ac)] / (2a)
=[5 +or- 14.73] / (2*6)
= (5 + 14.73)/12 or (5 - 14.73)/12
= 1.644 or -0.811
These two are solutions of your given equation.
Thank you.
2007-11-30 18:06:34 · answer #3 · answered by Anonymous · 0⤊ 0⤋
[-b +or- sqrt(b^2-2ab)]/2a
6x^2-5x=8
ax^2+bx+c=y
correspond them
2007-11-30 17:49:26 · answer #4 · answered by Anonymous · 0⤊ 0⤋