Question

1) dada a função f(x)=-2x+3,determine. A)f(1)= B)f(-2)= C)f(-4)= D)f(-6)= E)f(5)= F)f(1/2). G)f(2/5)= H)f(-2/7)=

Answer 1

1) dada a função f(x)=-2x+3,determine.

f(x) = - 2x + 3
 A)f(1)=
f(1) = - 2(1) + 3
f(1) = - 2 + 3
f(1) = 1

 B)f(-2)=
f(-2) = - 2(-2) + 3
f(-2) = + 4 + 3
f(-2) = 7

C)f(-4)=
f(-4) = - 2(-4) + 3
f(-4) = + 8 + 3
f(-4) = 11

 D)f(-6)=
f(-6) = - 2(-6) + 3
f(-6) = + 12 + 3
f(-6) = 15

 E)f(5)=
f(5) = - 2(5) + 3
f(5) = - 10 + 3
f(5) = - 7

F)f(1/2).
f(1/2) = - 2(1/2) + 3
f(1/2) = - 2(1)/2 + 2
f(1/2) = - 2/2 + 3
f(1/2) = - 1 + 3
f(1/2) = 2

 G)f(2/5)=
f(2/5) = - 2(2/5) + 3
f(2/5) - 2(2)/5 + 3
f(2/5)  = - 4/5 + 3            ( - 4/5 = - 0,8)
f(2/5) = - 0,8 + 3
f(2/5) = 2,2
f(2/5) = 22/10   ( divide AMBOS por 2)
f(2/5) = 11/5

H)f(-2/7)=
f(-2/7) = - 2(-2/7) + 3
f(-2/7) = + 2(2)/7 + 3
f(-2/7) = 4/7 + 3
                 4
f(-2/7) = ------ + 3
                 7

              1 + 21              22
F(-2/7) = ------------- = ----------
                    7                 7

f(-2/7) = 22/7