Tuesday, October 16, 2012

If x^2+ kx - 6 = (x - 2)(x + 3), then k = ?

Given that x^2 + kx - 6 =
(x-2)(x+3)


We need to find
k.


First we will need to open the brackets on the left side
and then compare the terms.


==> x^2 + kx -6 = x^2
-2x + 3x - 6


==> x^2 + kx -6 = x^2 + x
-6


Now we will add 6 to both
sides.


==> x^2 + kx = x^2 +
x


Now we will subtract
x^2


==> kx = x


Now we
will subtract x from both sides.


==> kx -x =
0


Now we will factor
x.


==> x (k-1) = 0


x
can not be zero.


Then k-1 = 0  ==> k=
1


Then the value of k is
1.

No comments:

Post a Comment

Calculate tan(x-y), if sin x=1/2 and sin y=1/3. 0

We'll write the formula of the tangent of difference of 2 angles. tan (x-y) = (tan x - tan y)/(1 + tan x*tan y) ...