How to solve this type of question (3m/s in 100m)

How many kilometers are equal to 5 miles? use 1 mile ≈ 1.61 kilometers. !

3x + 4y = 5 x- 3y = -7 solve by substitution

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