Answer:
f(x)=x^2+3
f(x+y)=(x+y)^2+3
this is done by replacing x with (x+y)
f(x+y)=x^2+2xy+y^2+3
therefore : f(x+y)= x^2+y^2+2xy+3
Answer:
second one
Step-by-step explanation:
am pretty sure
You can see that the term 
appears in both equations. In this cases, we can leverage this peculiarity and subtract the two equations to get rid of the repeated term. So, if we subtract the first equation from the second, we have
Now that we know the value of 
, we can substitute in any of the equation to deduce the value of 
: if we use the first equation, for example, we have
It would take Olive 30 minutes to walk home from the news station.
