Question

Verifique se -4 é raiz da equação 2z - 5z + 12 = 0

Answer 1

$\displaystyle \mathsf{2z-5z+12=0}\\\displaystyle \mathsf{2(-4)-5(-4)+12=0}\\\displaystyle \mathsf{-8-(-20)+12=0}\\\displaystyle \mathsf{-8+20+12=0}\\\displaystyle \mathsf{-8+32=0}\\\displaystyle \mathsf{24=0(falso)}$