a) x^2 +7x-8 = m(x)
ta có a+b+c= 0 <=> 1+7-8=0
=> x1 = 1; x2 = -8
b) ( x-3 ) ( 16-4x) = g(x)
<=> ( x-3) . 4 ( 4-x)=0
<=> 4-x=0 => x= 4 hoặc x-3=0 => x=3
c) 5x2+9x+4 =n(x)
ta có a-b+c <=> 5-9+4=0
=> x1= -1 ; x2= -4/5
d) ( 5x-2) - ( x-6) = b(x)
<=> 5x-2-x+6=0
<=> 4x +4 =0 => x=4
e)x2-5x + 6=c(x)...