Question

30 PONTOS PRA QUEM RESOLVER 
Seja a função f dada por f(x) = 3x +1, nessas condições qual o valor de:
a) 2 .f(-3 ) + f(-1) – 5. f(2)
b) f(1) + 3. f(5) – 2. f(-3)

Answer 1

f(-3)=3,(-3)+1=-9+1=8
f(-1)=3.(-1)+1=-2
f(2)=3.2+1=7
{2.-8+(-2)-5,7}=-53//a
f(1)=3+1=4
f(5)=3.5+1=16
{4+3.16-2,-8}=68//b

Answer 2

a)

$2\cdot\,f(-3)+f(-1)-5\cdot\,f(2)=\\2\cdot(3\cdot-3+1)+(3\cdot-1+1)-5\cdot(3\cdot2+1)=\\2(-9+1)+(-3+1)-5(6+1)=\\2\cdot-8-2-5\cdot7=\\-16-2-35=\\\boxed{-53}$

b)

$f(1)+3\cdot\,f(5)-2\cdot\,f(-3)=\\(3\cdot1+1)+3\cdot(3\cdot5+1)-2(3\cdot-3+1)=\\(4)+3(15+1)-2(-9+1)=\\4+3\cdot16-2\cdot-8=\\4+48+16=\\\boxed{68}$