he equation of any horizontal line is
y = .. a number
The x-value has no effect on the equation or on the line at all, as long as y-value stays the same.
In this case the line passes though the point (−8,9)
which tells us that the y-value we want is 9.
Therefore the equation is y=9
What is your first expression? because i can not answer without the first expression.
Can you show us a picture....
A pile of CD is 40 centimeters high
each CD is 8 millimeters
1 centimeter = 10 millimeters
40(10) = 400 millimeters high
400/8 = 50
50 CD in alll
hope this helps