Question

Factor 2x2 - 9x - 11.

Answer 1

Since 2 and 11 are prime we have
(2x 1)(1x 11) or
(2x 11)(1x 1)
we just need to figure out the signs

remember
(ax+b)(cx+d)=acx^2+bcx+adx+bd
the middle term coeficient is bc+ad
so
2x times 11=22x
1x times 1=x
there is not way to add or subtract 22x and x to get -9x

1st one is wrong

(2x 11)(x 1)

2x times  1=2x
11 times x=11x
11x-2x=9x

the 2x or the 1 has to  have the negative

(2x+11)(x-1)