Help please this is so hard for me this math

Three times the sum of a number and seven is negative thirty-six. what is the number?

One astronomical unit (1 au) is about 1.496 alt tag missing. kilometers. if you wrote this number of kilometers in regular decimal notation (for example, 528 and 3,459 are written in regular decimal notation), how many zeros would your number have?

Iam at home. /: i am playing video games. translate the following statement into symbolic form.