a^2-2a+3a-6=a^2+a-6
20-5x-4x-x^2=-x^2-9x+20
(a + 3)(a - 2) =a^2-2a+3a-6=a^2+a-6
(5 - x)(4 - x)= 20-5x-4x+x^2= x^2-9x +20
a^2-2a+3a-6=a^2+a-6
20-5x-4x-x^2=-x^2-9x+20
(a + 3)(a - 2) =a^2-2a+3a-6=a^2+a-6
(5 - x)(4 - x)= 20-5x-4x+x^2= x^2-9x +20