Explanation:
f(10)=10
f(-2)=-2
f(a)=a
f(a+b)=a+b
g(10)=5×10-12=3
g(-2)=5×(-2)-12=-10-12=-22
g(a)=5×a-12=5a-12
g(a+b)=5×(a+b)-12=5a+5b-12
h(10)=(10)^2 +4(10)-7=100+40-7=133
h(-2)=(-2)^2 +4(-2)-7=4-8-7=-11
h(a)=a^2 +4a -7
h(a+b)=(a+b)^2 +4a+4b-7=a^2+2ab+b^2+4b-7