What 3 questions do we ask ourselves when solving equations?

What is 20+(5 x 2/5 )+ 3 show your work

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.

The sum of the squares of two numbers is 8 . the product of the two numbers is 4. find the numbers.