Answer:
Part 11a) The slope of the line is 
Part 11b) The equation of the line is 
Part 11c) The value of a is 7 and the value of b is 7
Part 11d) The y-coordinate is -1
Step-by-step explanation:
Part 11a) Find the slope of the line
we know that
we know that
The formula to calculate the slope between two points is equal to

take two points from the graph
(3,3) and (8,13)
substitute



Part 11b) Write the equation for the line
<em>step 1</em>
Find the equation of the line in point slope form

we have


substitute

<em>step 2</em>
Convert to slope intercept form

isolate the variable y

Part 11c) Find the values for a and b
<em>step 1</em>
Find the value of a
we have the ordered pair (5,a)
so
x=5, y=a
substitute the value of x in the linear equation and solve for y

so
The value of a is 7
<em>step 2 </em>
Find the value of b
we have the ordered pair (b,11)
so
x=b, y=11
substitute the value of y in the linear equation and solve for x

so
The value of b is 7
Part 11d) What is the y-coordinate when the x-coordinate is 1?
For x=1
substitute in the linear equation

therefore
The y-coordinate is -1