If f 1 4 and f x y f x f y 7xy 4 Then f 2 f 5

Given f(1)=4,
also given f(x)+f(y)+7xy+4------(i)
Let us tahe (x,y)=(1,1) and subst in equ (i)
f(2)=f(1)+f(1)+(7*1*1)+4=19;similarly solve for other two f(3),f(4),f(5)
we get f(3)=41
f(4)=70
f(3+2)=f(3)+f(2)+(7*3*2)+4=106
Therefore f(2)+f(5)=19+106=125.
10 years agoHelpfull: Yes(6) No(1)
we know that f(1)=4
given that f(x+y)=f(x)+f(y)+7xy+4
f(2)=f(1)+f(1)=4+4+7(1)(1)+4=19.
f(3)=f(2)+f(1)=19+4+7(2)(1)+4=41.
f(5)=f(2)+f(3)=41+19+7(2)(3)+4=106
10 years agoHelpfull: Yes(3) No(8)
f(2)=4+4+7+4=19
f(4)=f(2+2)=19+19+28+4=70
f(5)=f(4+1)=70+4+28+4=106
f(2)+f(5)=19+106=125
10 years agoHelpfull: Yes(1) No(1)
f(1)=4
f(1+1)=f(2)=f(1)+f(1)+7*1*1+4=4+4+7+4=19
f(1+2)=f(3)=f(1)+f(2)+7*1*2+4=4+19+14+4=41
f(2+3)=f(5)=f(2)+f(3)+7*2*3+4=19+41+42+4=106
f(2)+f(5)=19+106=125
ans=125
10 years agoHelpfull: Yes(1) No(1)
f(2)=4+4+7+4=19
f(4)=f(2+2)=19+19+28+4=70
f(5)=f(4+1)=70+4+28+4=106
f(2)+f(5)=19+106=125
10 years agoHelpfull: Yes(0) No(2)

If f(1)=4 and f(x+y)=f(x)+f(y)+7xy+4,
Then f(2)+f(5)=?