I believe that the answer is -18.
we know that
The formula to calculate the slope between two points is equal to

<u>Part a) Find the slope of line PQ</u>

substitute in the formula


Any line parallel to X-axis has slope equal to zero
so
the line PQ is parallel to the x-axis
therefore
<u>the answer Part a) is </u>

<u>Part b) Find the slope of line MN</u>

substitute in the formula


Anything divided by zero is undefined
m=undefined
therefore
<u>the answer Part b) is </u>
undefined
<u>Part c) How are the two lines related ? </u>
we know that
Any line perpendicular to X-axis has slope undefined
Because the term
will always be zero
so
<u>the answer Part c) is</u>
the lines are perpendicular
Answer:
Line A
Step-by-step explanation:
A line of symmetry is a line that divides a shape into exactly two equal halves.
A triangle is a polygon with three sides and three angles. A scalene triangle has no lines of symmetry, an isosceles triangle has more than one line of symmetry while an equilateral triangle has three lines of symmetry.
From the diagram we can see that line A divides the figure into two equal halves, hence line A is the line of symmetry.
Rearrange the equation to get:
y = 3x - 7
From this you can see that:
m = 3, b = -7