What is the purpose of diagrams in informational text to present the main idea to define specialize vocabulary in the text to summarize information in a visual way to make clear supporting details

The purpose of a diagram in an informational text is to summarize information in a visual way.

An informational text is part of the non fiction category, it aims to share  knowledge about the natural or social world. For that instance diagrams come in handy when trying to understand a process description, like    photosynthesis.

A diagram can help us understand and remember ideas  because it's a graphic aid that sumarizes information using visual resources.    

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4

answer: common sense was the pamphlet that thomas paine used to convince reluctant americans to abandon the goal of reconciling with britain and to accept that independence was the only option to preserve their liberty.