Question

Determine o zero das funções a seguir:
a) y = 5x + 25
b) y = x + 4
c) y = 3x - 21

Answer 1

$\mathtt{a)~y=5x+25} \\ \mathtt{5x + 25 = 0} \\ \mathtt{5x = -25} \\ \mathtt{x = -25\div 5 } \\ \mathtt{x = -5} \\ \\ \mathtt{b)~y = x+4} \\ \mathtt{x + 4= 0} \\ \mathtt{x = -4} \\ \\ \mathtt{c)~y= 3x-21} \\ \mathtt{3x - 21 = 0} \\ \mathtt{3x = 21} \\ \mathtt{x = 21\div3} \\ \mathtt{x = 7}$