Question

Dada a função f: IR -> IR definida por f(x) = - 4x + 3, determine o valor de x para que:
a) f(x) = - 4 b) f(x)= 1/2

Answer 1

a)
f(x) = - 4x + 3
-4 = -4x + 3
-4 -3 = -4x
-7 = -4x
x = 7/4

b)
1/2 = -4x + 3
1 = 2(-4x + 3)
1 = -8x + 6
1 - 6 = -8x
-5 = -8x
x = 5/8

Ik_Lob

Answer 2

 f(x) = - 4x + 3, determine o valor de x para que:


a) f(x) = - 4

 - 4x + 3= - 4 ==(-1) ==> 4x -3=4==> 4x = 4+3 ==> 4x = 7 ==> x = 7/4

b) f(x)= 1/2

 - 4x + 3= 1/2 ==(-1) ==> 4x -3=1/2==> 4x = 1/2+3 ==> 8x =(1+6) ==> 8x = 7==> x=7/8