Question

Simplify the rational expression. State any restrictions on the variable.

Answer 1

can you factorise \((k^2-k-2)=(k+...)(k-...)\)

Answer 2

uhh no :/

Answer 3

can you use the quadratic formula?

Answer 4

how do i use that ?

Answer 5

\[ax^2+bx+c=0\]\[x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\]

Answer 6

does that look like some thing you can deal with, or should i tried to explain factoring a different way?

Answer 7

explain in a diff way please

Answer 8

ok

say we have a quadratic

\[(x+a)(x+b)\\=x^2+ax+bx+ab\\=x^2+(a+b)x+ab\]

Answer 9

yess do we solve that ??

Answer 10

in your case

\[(k^2−k−2)=(k+a)(k+b)=k^2+(a+b)+ab\]

\[a+b=-1\\ab=-2\]

you have to find \(a,b\)

Answer 11

if you look at the (positive and negative) factors of negative two

−2=(±1)(∓2)

there are only two pairs

a,b=1,−2
or
a,b=−1,2


which of these

satisfies a+b=−1 ?

Answer 12

which is true

1+-2 = -1 ? or -1+2 = -1 ?

Answer 13

would it be -1+2=-1