Answer:
f(x) = -5/3 x +44/3
Explanation:
helo : let f(x)= ax+b
f(4) = 8 means : a(4)+b=8 and f(7) = 3 means : a(7)+b=3
you have this system : 4a +b = 8....(*)
7a+b = 3 ....(**)
solve this system use (*) : b = 8 -4a and use (**) : b = 3-7a
so : 8-4a = 3-7a
-4a+7a = 3-8
3a = -5 so a = -5/3
but b =8-4a so : b= 8-4(-5/3) =8+20/3 =44/3
f(x) = -5/3 x +44/3