I don’t understand is there more to the question?
All you have to do is draw a line on all the posible numbers that can be x makes sure to draw a arrow at the end of the number line. Either that or draw grapshs a dot on every number less then 3. sorry if its worng :)
Answer:
Number 4: Using Pythagoras Theorem,

Number 5:

3:
It is a right triangle
4:
Not a right triangle
For the last one:

Rounded down (because the answer needs to be a whole number) is 21
64
Step-by-step explanation:

Answer:
ac + 4 = b
Step-by-step explanation:
Step 1: Write equation
a = (b - 4)/c
Step 2: Multiply both sides by <em>c</em>
ac = b - 4
Step 3: Add 4 on both sides
ac + 4 = b