What is 3r-2 ?? Algebra is not my strong suit

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

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1

Graph the system of inequalities presented here on your own paper, then use your graph to answer the following questions: y < 4x − 8 y is greater than or equal to negative 5 over 2 times x plus 5 part a: describe the graph of the system, including shading and the types of lines graphed. provide a description of the solution area. (6 points) part b: is the point (5, −8) included in the solution area for the system? justify your answer mathematically. (4 points)