use the quadratic formular to solve the equation. 3x^2 - 22x = 13?

Hi,

3x² - 22x - 13 = 0
.............._____________
-(-22) ± √(-22)² - 4(3)(-13)
----------------------------------- = x
....................2(3)

.........________
22 ± √484 + 156
----------------------- = x
.............6

.........___
22 ± √640
--------------- = x
.........6

...........__
22 ± 8√10
--------------- = x
.........6

...........__
11 ± 4√10
--------------- = x <==ANSWER
.........3

x ≈ 7.88 or -.55 <== rounded decimal answers

I hope that helps!! :-)

quad. formula is ::
[-b +/- SQRT (b^2 - 4ac)] divided by 2a

in your equation a = 3, b = -22, c = -13
plug it in, and you must obtain 2 values for x. One + and one - sonce there is a part that says plus or minus (+/-)

heres the deal, the quadratic formula was only taken from the basic equation: ax^2 + bx + c = 0
but the deal is if we dont need to use it: we use factoring but if the equation cannot be factorable, we use the formula...
======== _______
so: -b +/- √b^2 - 4ac
----------------------------------
=======2a
/
/
/
========______________
-(-22) +/- √(-22)^2 - 4(3)(-13)
---------------------------------------
2(3)
/
/
======__________
22 +/- √484 - (-156)
-----------------------------
6
/
/
/
======___
22 +/- √640
-----------------
6
/
/
/
=======__
22 +/- 8√10
-----------------
6
/
/
/
FINAL:
/
/
======__
11 + 4√10
---------------
3
/
/
/
AND
/
/
/
======__
11 - 4√10
---------------
3

3x^2 - 22x = 13
3x^2 - 22x - 13 = 0
x = [-b ±√(b^2 - 4ac)]/2a

a = 3
b = -22
c = -13

x = [22 ±√(484 + 156)]/6
x = [22 ±√640/6
x = [22 ±25.29]/6 (approx.)

x = [22 + 25.29]/6
x = 47.29/6
x = 7.881

x = [22 - 25.29]/6
x = -3.29/6
x = -0.548

∴ x = -0.548 , 7.881 (approx.)

f

It's: 22+/- (8 SQRT 10) / 6

Hope I helped...

3x² - 22x - 13 = 0
x = [ 22 ± √ (484 + 156 ) ] / 6
x = [ 22 ± √ (640 ) ] / 6
x = [ 22 ± 8√10 ] / 6
x = [ 11 ± 4√10 ] / 3