Hello.
First, let the number be r.
5 times r is written like this:

Now, add 45:

Now, the sum of 5r+45 is equal to the sum of 85 and 140:

In order to solve this equation, we need to add 85 and 140:

Now, subtract 45 from both sides:



The last step is to divide both sides by 5:

Therefore, the answer is

I hope it helps.
Have a nice day.

4023/x=100/75
(4023/x)*x=(100/75)*x
4023=1.3333333333333*x
x=4023/1.3333333333333
x=3017.25
Loretta:
Average driving speed = 55 mph
Time = 4 hours
Distance traveled = 55*4 = 220 miles
Dad:
Average driving speed = 65 mph
Let x = hours driven
Distance traveled = 65x miles
The length of the trip is 610 miles, therefore
65x + 220 = 610
65x = 390
x = 6 hours
Answer: Loretta's dad drove for 6 hours.
Well, you could subtract or add or multiply or divide for example 45 + x=50 you could subtract 50 from 45 and get 5 there are many ways you can find missing values.
There are a 100 cm in one meter so 6 m= 600 cm so 30 cm/ 600 cm = 1 cm/ 20cm or 0.05. Convert that into a percentage and you get 5%.
30cm is 5% of 6 m.