Question

Me ajudem não consegui resolver!

Answer 1

(x-1).(x-2)= 12

x^2-2x-x+2= 12

x^2-3x+2= 12

x^2-3x+2-12=0

x^2-3x-10=0

∆=b^2-4.a.c

∆=(-3)^2-4.(1).(-10)

∆= 9+40

∆= 49

x=-b+-√∆
___---------
____2.a

x= -(-3)+-√49
____-------------
______2.1

x= +3+7
___-------
____2

x'= 10/2

x'= 5

x"= +4-7
___---------
____2

x"= -3/2