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
