iwona wrote:If (t-8)is a factor of t2-kt-48 then k=
How to figure out that t=8?
Thanks so much![/img][/list]
When we solve x^2+x-6=0, we get:
(x+3)(x-2) = 0.
Thus, the equation has two factors: (x+3) and (x-2).
The roots of the equation are the values of x that make the factors equal 0: x=-3 and x=2.
Thus, if we know one of the factors of an equation, we automatically know a root: it will be the value that makes the factor equal 0.
In the problem above, since (t-8) is a factor of the equation, we know that t=8 is one of the roots.
To solve for k, just plug t=8 into the equation t^2-kt-48=0 and solve:
t^2-8k-48=0
8^2-8k-48=0
-8k=-16
k=2.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
