Question

f:R--R, f(x) =ax+b, a, b apartine R A(-1,2) B(2,-1) ​

Answer 1

f(-1)=2 ⇒-1a+b=2 ⇒ b=a+2

f(2)=-1 ⇒2a+b=-1 ⇒2a+a+2 =-1 ⇒a=-1, b= 1 ⇒f(x)=-x+1