Resposta :
(x + 4)(x – 1) + x2 = 5(x – 1)
x² -x +4x -4 +x² =5x -5
x² +x² -x+4x-5x-4+5=0
x² +x² -x-5x+4x-4+5=0
x² +x² -6x +4x -4+5=0
2x² -2x +1=0
a=2 , b=-2 , c= +1
▲= b² -4.a.c= (-2)² -4.(2)(+1)= +4-8=-4
x² -x +4x -4 +x² =5x -5
x² +x² -x+4x-5x-4+5=0
x² +x² -x-5x+4x-4+5=0
x² +x² -6x +4x -4+5=0
2x² -2x +1=0
a=2 , b=-2 , c= +1
▲= b² -4.a.c= (-2)² -4.(2)(+1)= +4-8=-4