5(2x - 8) + 15 = -15
-15 -15 subtract 15 from each side
5(2x - 8) = -30
÷5 ÷5 divide both sides by 5
2x - 8 = -6
+8 +8 add 8 to each side
2x=2
÷2 ÷2 divide both sides by 3
x = 1
Checking:
5(2(1)-8) + 15 = -15
5(-6) + 15 = -15
-30 + 15 = -15
-15 = -15 Correct! x=1
Each floor is 3.35 feet taller than each floor of the Aon Center
X - y = 9
x + 2y = 27
You can subtract the top equation from the bottom
3y = 18
y = 6
x = 15
The two numbers are 15 and 6
As the time go the grass height go through increasing and decreasing
The domain is

and the range is

Domain is x values (horizontal axis), while range is y values (vertical axis). On a line like this one, domain is calculated from the left most point to the right most, while range is calculated from the down most to the upmost.
Because this line is a solid line rather than a dotted line, less than or equal to

signs are used rather than just

less than signs.