Answer:
3) 
4) a) 
b) 
Step-by-step explanation:
<u>Exercise 3</u>



<u>Exercise 4</u>
a) If L2 is parallel to L1, it has the same slope (gradient) ⇒ 
If L2 passes through point (3, 1):



So L2 = L1
b) If L3 is perpendicular to L1, then the slope of L3 is the negative reciprocals of the slope of L1 ⇒ 
If L3 passes through point (-5, 2):



$6.24. This is because 1.44 / 6 = 0.24, and 0.24 x 26 = 6.24.
So you subtract, 27-22. 27-22 is equal to 5. So, John will buy 5 kinds of T- Shirts.