Well if there is 28 feet, that would be (12x28) 336 inches, and 16 inches between the plug and the first light, there would be only 320 inches left for lights. therefore, if there are 4 inches between each light, we divide 320 by 4. the answer we get is 80. there are 80 lights.
For this case we have the following functions:

We must find
when
.
So:

We apply distributive property to the terms within parentheses taking into account that:

We add similar terms taking into account that different signs are subtracted and the sign of the major is placed:

Thus, we have to:

Then, with x = 2:

Equal signs are added and the same sign is placed.
Answer:

The answer is 60 you just multiply the length and width and height
Answer:
1. Complimentary angles
2. 3x+20 = 10x-15: x = 5
3. I'm not sure on part 3, sorry.
1. The number 3 is located in the hundred thousands place.
2. Since the number 4 is located in the ten thousands place, it's telling 3 to stay the same
Stays the Same: 1,2,3,4
Goes Up: 5,6,7,8, etc...
342,802 ⇒ 300,000