Answer:
a. 
b. 
c. 
d. 
Step-by-step explanation:
Gradient is just another similar term for slope l,
, and it can be calculated by
where
and 1
is the
-coordinates of point 
We let
be point
and
be point
, we can then write the equation:
.
It also says that the points are with a gradient of
so
. We can then write the equation:

Finding
If
:

Writing an expression for
in terms of
.

Writing an expression for
in terms of 

Finding
if 

Step-by-step explanation:
12 to the 2nd power=144
15 to the 2nd power =225
225-144=81
square root of 81 is 9
If you want to know the answer you need to give us the question.