Câu trả lời:

a/ y=f(x)=-2x+3

f(-2)=-2*(-2)+3=7

f(-1)=-2*(-1)+3=5

f(0)=-2*0+3=3

f(-1/2)=-2*-1/2+3=4

f(1/2)=-2*1/2+3=2

b/y=g(x)=x^2-1

g(-1)=-1^2-1=-2

g(0)=0^2-1=-1

g(2)=2^2-1=3