Plug in 9 where "a " is. so it reads "6x9+13" then solve. so 6x9=54 then 54+13=67
Answer:
The graph is attached.
Step-by-step explanation:
+
= 
= -
+ 
Multiplying both sides by 4 gives;
y =
+ 6
You can graph this solution using a graphing calculator to get the answer as attached.
16/12 = (x-1)/6
x-1 = 4/3 . 6
x = 24/3 + 1 = 9
32/24 = (y+1)/21
y+1 = 4/3 . 21
y = 84/3 - 1 = 25