{{ toc.name }}
{{ toc.signature }}
{{ toc.name }} {{ 'ml-btn-view-details' | message }}
{{ stepNode.name }}
{{ 'ml-toc-proceed' | message }}
Lesson
Exercises
Recommended
Tests
An error ocurred, try again later!
Chapter {{ article.chapter.number }}
{{ article.number }}. 

{{ article.displayTitle }}

{{ article.intro.summary }}
{{ 'ml-btn-show-less' | message }} {{ 'ml-btn-show-more' | message }} expand_more
{{ 'ml-heading-abilities-covered' | message }}
{{ ability.description }} {{ ability.displayTitle }}
{{ 'ml-heading-lesson-settings' | message }}
{{ 'ml-lesson-show-solutions' | message }}
{{ 'ml-lesson-show-hints' | message }}
{{ 'ml-lesson-number-slides' | message : article.intro.bblockCount}}
{{ 'ml-lesson-number-exercises' | message : article.intro.exerciseCount}}
{{ 'ml-lesson-time-estimation' | message }}

Theory

Subtraction Property of Equality

When rewriting equations it's important to make the the same operation on both sides to ensure that the equality still holds. So, if one side is subtracted by a number, the other side must be subtracted by the same number. In the equation both sides can be subtracted by