Answer:
你看chart的triangle你看the dimension
Step-by-step explanation:
x = 7/9
f(x)= 3x-4
f(-1)= 3*-1-4
f(-1)= 2-4
f(-1)= -2
f(3)= 3*3-4
f(3)= 9-4
f(3)=5
f(1)= 3*1-4
f(1)= 3-4
f(1)= -1