3(g+4g) in distributive property

Liz is shipping a package to her friend. the maximum weight of a medium flat-rate box is 20 pounds, including the box which weighs 6 ounces. write and solve an inequality to describe the possible weight in pounds, w, of the contents that liz will ship to her friend if she must use a medium flat-rate box. use the drop-down menus to explain your answer.

How to do a maths question? i have a mock

Given the equation −4  = 12, solve for x and identify if it is an extraneous solution.