4xplus 5 5y equals -10

Did you mean 20? Can’t figure out my answer for that, only for a 20:(

Step-by-step explanation:

4x+5 5y=-10

4x +5+5y= -10

bring the 4x and 5y together and take +5 to the other side

4x +5y= -10-5

4x + 5y= - 15

you can't go further in simplifying it

"The number of hours of daylight each day" is the one natural phenomenon among the choices given in the question that is the best example of periodic behavior. The correct option among all the options that are given in the question is the fourth option or option "D". I hope that the answer has come to your help.