From the slope form of a line;

y-b=bx-ab
y=bx-ab+b
y=bx-b(a-1)
y=5/3x
this is because f(x)=x is one of (identity function) the 12 basic functions and when you multiply it it will shift it on the y axis
If you were to do y=x+5/3 it would make a horizontal shift to the left 5/3
So the unit your on is mostly about knowing the number located in the function that will make the graph shift different ways
Step-by-step explanation:
1. Right angled triangle , scalene triangle
2. isosceles triangle, obtuse angled triangle
3. equilateral triangle
4. right angled triangle, isosceles triangle
5. scalene triangle, obtuse angled triangle
6. scalene triangle, acute angled triangle