Скачать или смотреть Simplifying linear expressions (8th grade math/algebra 1)

We look at linear expressions that have parentheses, focusing on those where a quantity is multiplied by a negative number, or just has a negative sign in front, such as: 14x - 9(3x - 5) or 7s + 2 - (-10 - 6s).

You just have to be careful with the signs, when using the distributive property with these.

When there is just a minus sign, you can imagine a one in front of the quantity in parentheses. As a shortcut, the sign of each term inside parentheses changes to the opposite, in that situation. As an example, 7s + 2 - (-10 - 6s) simplifies first to 7s + 2 + 10 + 6s.

Then we also solve an equation where this new skill is useful.

Math Mammoth Grade 8 curriculum
https://www.mathmammoth.com/complete/...