SOLUTION: Use the quadratic formula to find the solutions to the quadratic equation below. Check all that apply. 3x^2 - x - 2 = 0 A. - 2/3 (both are negative) B. -1 C. 3/

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Use the quadratic formula to find the solutions to the quadratic equation below. Check all that apply. 3x^2 - x - 2 = 0 A. - 2/3 (both are negative) B. -1 C. 3/      Log On


   

Question 145001: Use the quadratic formula to find the solutions to the quadratic equation below. Check all that apply.
3x^2 - x - 2 = 0
A. - 2/3 (both are negative)
B. -1
C. 3/2
D. -4/5 (only 4 is negative)
E. 1
F. 5/4

Found 2 solutions by jim_thompson5910, vleith:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%28-1%29+%2B-+sqrt%28+%28-1%29%5E2-4%283%29%28-2%29+%29%29%2F%282%283%29%29 Plug in a=3, b=-1, and c=-2


x+=+%281+%2B-+sqrt%28+%28-1%29%5E2-4%283%29%28-2%29+%29%29%2F%282%283%29%29 Negate -1 to get 1.


x+=+%281+%2B-+sqrt%28+1-4%283%29%28-2%29+%29%29%2F%282%283%29%29 Square -1 to get 1.


x+=+%281+%2B-+sqrt%28+1--24+%29%29%2F%282%283%29%29 Multiply 4%283%29%28-2%29 to get -24


x+=+%281+%2B-+sqrt%28+1%2B24+%29%29%2F%282%283%29%29 Rewrite sqrt%281--24%29 as sqrt%281%2B24%29


x+=+%281+%2B-+sqrt%28+25+%29%29%2F%282%283%29%29 Add 1 to 24 to get 25


x+=+%281+%2B-+sqrt%28+25+%29%29%2F%286%29 Multiply 2 and 3 to get 6.


x+=+%281+%2B-+5%29%2F%286%29 Take the square root of 25 to get 5.


x+=+%281+%2B+5%29%2F%286%29 or x+=+%281+-+5%29%2F%286%29 Break up the expression.


x+=+%286%29%2F%286%29 or x+=++%28-4%29%2F%286%29 Combine like terms.


x+=+1 or x+=+-2%2F3 Simplify.


So our answers are x+=+1 or x+=+-2%2F3


Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
3x^2 - x - 2 = 0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ a=3, b=-1 c =-2
x+=+%281+%2B-+sqrt%28+1%2B24%29%29%2F%286%29+
x+=+%281+%2B-5%29%2F%286%29+
x = 6/6 x = -4/6=-2/3
So A and E