Answer:

Step-by-step explanation:
Given

Required
Determine the expression for s
The speed is calculated as:

Substitute S for speed

Let the number of books be b and the time be m.
The expression becomes

Hence, the expression for the scenario is:

Answer:
30 Hours
Step-by-step explanation:
8h=240
240÷8=30
Start by multiplying 1.2 and 7.5 which will give you 9.Then you have 9-8/4. so then you do 8 divided by 4 which is 2. so you have 9-2 and that equals 7.
What we want to do first is isolate the variable. To do this we need to multiply each side by 5 to remove the fraction
5 * 5 = 5*

w
Simplify the right side
5 *

w = 1w
Now simplify the left side
5 * 5 = 25
Then we get...
25 = w
There's your answer!