Wednesday

July 23, 2014

July 23, 2014

Posted by **Anonymous** on Tuesday, December 25, 2012 at 3:56pm.

x^2-2=9x

My answer: x=9/2+or- the sqrt. of 22.25

(but when I checked my answer the actual answer was x=9+or - the sqrt. of 89 and then all over 2)

Please explain why my answer is different from the actual answer.

- Algebra 2 .. -
**Steve**, Tuesday, December 25, 2012 at 4:49pmx^2 - 9x = 2

x^2 - 9x + (9/2)^2 = 2 + (9/2)^2

(x - 9/2)^2 = 89/4

x = 9/2 ± √(89/4)

x = 9/2 ± √22.25

but you could also factor out the 1/4 in 89/4 and say

x = 9/2 ± √89/√4

x = 9/2 ± √89/2

x = (9 ± √89)/2

these exercises usually want things as fractions rather than decimals, and the quadratic formula usually expresses the answers as they did.

**Related Questions**

Algebra 2 .. - Solve the equation by completing the square. 3x^2+4x=1 My answer...

math,correction - Is this correct now. Problem #1 solve by completing the square...

algebra - 1)Solve by factoring:5x^2=4-19x answer=-4,1/5 2)Which quadratic ...

math,help,algebra I - I need help can someone help me get unstuck and let me ...

maht,correction please - Problem #1 Solve by completing the square 2x^2-4x-11=0 ...

Algebra - I was given this answers to a problems I solved but I do not ...

Algebra - I was given this answers to a problems I solved but I do not ...

Algebra - 1)Solve by factoring:5x^2=4-19x answer=-4,1/5 2)Which quadratic ...

Algebra 2 - Completing the square method allows you to solve any quadratic ...

algebra - can someone tell me if i did the problem correct (solve by completing ...