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
Just multiple them together and u get 693
The correct answer is 196 or Option A.
The explanation is just as complicated as the question.
The x=7y-4 one and put it to where the x in the other equation is.
Well not getting any of the answers :/ i get 1184
