On the first day of june, there were about 17.71 h of daylight in a city. five months later, there were about 5.30 h of daylight. what was the percent decrease?

Percentage increases and decreases, are found by setting the problem up proportionally.

You are trying to find what percentage of 17.37 is 8.30 first.

so What %/100 = 8.30/17.37

Now define a variable:

Let x = What%  

x/100 = 8.30/17.37

17.37x = 830

x = 830/17.37

x ≈ 47.78

8.30 is approximately 47.78% of 17.37, so the percentage decrease is 100% - 47.78% = 52.22%

The percentage decrease is approximately 52.22%

the order of operations for 2 + (3 - 9) / -3 * 4 is 1. subtraction, 2. division, 4. multiplication, and 3. addition.