Can someone me find the y-intercept due tomorrow pleasr

What is the value of the expression 9+n/3-6 when n = 12? 1. 5. 7. 12.

Ineed with this problem 21 show steps

Acaterer charges $500 plus $30 per guest to cater a wedding. walt and traci don't want to spend more than $8000 on catering. write and solve an inequality in terms of the number of guests, g, that can be invited. a) 30g ? 8000; g ? 267 b) 500g < 8000; g < 16 c) 500 + 30g < 8000; g < 250 d) 500 + 30g ? 8000; g ? 250