Question

13. Resolva estas equações com o Auxílio do exercício Anterior (lei do anulamento do Produto).

a) x(x+1)= 0
b) 2x(x-5)= 0
c) (x+3)(x-1)= 0
d) (x-6)(4x-8)= 0

Answer 1

$a) \\ x(x+1)=0 \\ \\ x+1=0~~~~ ~~x=0 \\ x=-1 \\ \\ S=\{-1,0\} \\ \\ b) \\ 2x(x-5)=0 \\ \\ x-5=0~~~~~~~2x=0 \\ x=5~~~~~~~~~~~~~~x=0 \\ \\ S=\{0,5\}$


$c) \\ (x+3)(x-1)=0 \\ \\ x+3=0~~~~~~~~~~~~x-1=0 \\ x=-3~~~~~~~~~~~~~~~x=1 \\ \\ S=\{-3,1\} \\ \\ d) \\ (x-6)(4x-8)=0 \\ \\ 4x-8=0~~~~~~~~~~~~x-6=0 \\ 4x=8~~~~~~~~~~~~~~~~~~x=6 \\ x=8\div4 \\ x=2 \\ \\ S=\{2,6\}$