Answer: 
Step-by-step explanation:
You need to analize all the information given in the exercise.
You know that the actual height of the T-rex on the projector lens is the following:

The height of the projected T-rex is:

Make the conversion from meters to centimeters:

Therefore, the scale factor will be:

Finally, you must substitute values into the equation and then you must evaluate in order to find the scale factor of the projection. You get that this is:

STEP 1:
convert meters to centimeters
100 cm= 1 meter
= 100 cm/m * 2.5 m
= 250 cm
STEP 2:
x= length of first shelf
2x+18= length of second shelf
x-12= length of third shelf
x+4= length of fourth shelf
since the whole board has to be used, add lengths of all shelves and set it equal to the whole length of the board (250 cm).
x + (2x+18) + (x-12) + (x+4)= 250 cm
combine like terms
5x + 10= 250
subtract both sides by 10
5x= 240
divide both sides by 5
x= 48
STEP 3:
find length of second shelf
= 2x + 18
= 2(48) + 18
= 114 cm
CHECK:
x + (2x+18) + (x-12) + (x+4)= 250
48 + (2(48)+18) + (48-12) + (48+4)= 250
48 + (96+18) + 36 + 52= 250
48 + 114 + 36 + 52= 250
250= 250
ANSWER: Shelf two is 114 cm.
Hope this helps! :)
Could you take a better picture please?
Answer:
It will be "q+5"
Step-by-step explanation:
When you add a number and a letter you just leave them like that. If you would to have a number multiplying a letter like "5q" and something else like "3q" when you add them together you will get "5q+3q=8q" In this case you can add them together because the number is multiplying the letter.