Question 962800
f(x)=2x+5
f(2)=9
f(3)=11
f(2)+f(3)=20
f(-1)=3
f(10)=25
f(-1)+f(10)=28
f(a)=2a+5
f(-2a)=-4a+5
f(a)+f(-2a)=-2a+10
f(a+2)=2(a+2)+5=2a+9
f(a-2)=2(a-2)+5=2a+1
f(a+2)+f(a-2)=4a+10