Repeated subtraction to divide 93 by 3

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

In the triangles, bc =de and ac fe.if the mzc is greater than the mze, then ab isdfelth