Question

Sejam f(2x+1)=x²+2x então f(2) vale:

a)5/4
b)3/2
c)1/2
d)3/4
e)/2

Answer 1

$Ola'! \\ \\ Iguale~assim~f(2x+1)=f(2)~,ent\~ao~resolvendo~seria: \\ \\ 2x+1=2 \\ \\ 2x=2-1 \\ \\ \boxed{x= \frac{1}{2}} \\ \\ como~ja~temos~valor~de~''x'', resolvemos~substituindo~observe: \\ f(2x+1)=x\²+2x \\ \\ f(2( \frac{1}{2})+1)= ( \frac{1}{2}) ^{2}+2( \frac{1}{2}) \\ \\ f(2)= \frac{1}{4}+1 \\ \\ \boxed{\boxed{f(2)= \frac{5}{4}}} \\ \\ Isso~e~todo~ok?, sucessos!... \\ \\ .$