Question

Calcule o zero de cada função: a f(x)= -x+9; (b) f(x)=2x+3/4; (c) f(x)= -1/5x-6

Answer 1

Basta trocarmos f(x) por 0:

a)
f(x) = -x +9
-x + 9 = 0
-x = -9 ×(-1)
x = 9

b)
f(x) = 2x +3/4
2x +3/4 = 0
2x = -3/4
x = (-3/4)/2
x = -3/8
x = -0,375

c)
f(x) = -1/5x -6
-1/5x -6 = 0
-1/5x = 6
-1 = 6.(5x)
-1 = 30x
x = -1/30
x = 0,033