Friday

August 22, 2014

August 22, 2014

Posted by **David** on Wednesday, December 12, 2012 at 2:58pm.

X^2-4x=21

- Math Help now !!!! Plz -
**drwls**, Wednesday, December 12, 2012 at 5:34pmLearn the quadratic formula:

x = [-b +/-sqrt(b^2 -4ac)]/2a

In your case a = 1, b = -4 and c = -21

x = [4 +/-sqrt(100)]/2

You finish it. You surely know what the square root of 100 is.

.

**Related Questions**

College Math II - Solve by using the quadratic formula. x^2 + 6x + 6 = 0 I am ...

math-calculus - solve equation |x^2-2x-6| using quadratic formula. i not get how...

math help plz - Use the quadratic formula to solve the equation: 0 = x2 - 5x + 6...

Math - Use the quadratic formula to solve each of the following quadratic ...

math - 1/2x^2=x/4+1 how can i solve that with quadratic formula?plz i need the ...

Math!Please Help Me! - Solve the following quadratic by either factoring or ...

Math - Using the quadratic formula solve xsquared=2/3x Using the quadratic ...

MATH,correction - IS THIS CORRECT NOW. solve by using the quadratic formula. x^2...

algebra II - I'm quite clueless as to how to solve this. I know the quadratic ...

Math ,help - how can i simplify this more its for the following problem: Problem...