SOLUTION: Solve by using the quadratic formula. I can not reach the correct answer for: 3x2-10x-21=0 I did: -(-10)+-(-10)2 -4(3)(-21) divided by 2(3) = 10=-100+252 divided by 6 10+-3

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Solve by using the quadratic formula. I can not reach the correct answer for: 3x2-10x-21=0 I did: -(-10)+-(-10)2 -4(3)(-21) divided by 2(3) = 10=-100+252 divided by 6 10+-3      Log On


   

Question 138740: Solve by using the quadratic formula. I can not reach the correct answer for:
3x2-10x-21=0
I did: -(-10)+-(-10)2 -4(3)(-21) divided by 2(3) =
10=-100+252 divided by 6
10+-352 divided by 6
10+-18.8 divided by 6
correct answer: 5+-2(rad)22 over 3. Please show me what I am doing wrong. Thank you for your attention.
Kathy
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The formula is x = [-b +- sqrt(b^2 - 4ac)]/2a
You forgot sqrt.
Cheers,
Stan H.