Example 10 - Chapter 8 Class 8 Algebraic Expressions and Identities

Last updated at April 16, 2024 by

Example 10 - Simplify (a + b) (2a - 3b + c) - (2a - 3b)c - Class 8

Example 10 - Chapter 9 Class 8 Algebraic Expressions and Identities - Part 2

Transcript

Example 10 Simplify (a + b) (2a – 3b + c) – (2a – 3b) c. Here there are two expressions 1st expression = (𝑎+𝑏) (2𝑎−3𝑏+𝑐) 2nd expression = (2𝑎−3𝑏) 𝑐 Solving 1st expression (𝑎+𝑏) (2𝑎−3𝑏+𝑐) = 𝑎(2𝑎−3𝑏+𝑐)+𝑏(2𝑎−3𝑏+𝑐) = (𝑎×2𝑎)−(𝑎×3𝑏)+(𝑎×𝑐)+(𝑏×2𝑎)−(𝑏×3𝑏)+(𝑏×𝑐) = 2𝑎^2−3𝑎𝑏+𝑎𝑐+2𝑎𝑏−3𝑏^2+𝑏𝑐 = 2𝑎^2−3𝑏^2+𝑎𝑐+𝑏𝑐−3𝑎𝑏 +2𝑎𝑏 = 2𝑎^2−3𝑏^2+𝑎𝑐+𝑏𝑐−𝑎𝑏 Solving 2nd expression (2𝑎−3𝑏)𝑐 = 2𝑎𝑐−3𝑏𝑐 Now, our expression is (𝑎+𝑏)(2𝑎−3𝑏+𝑐)−(2𝑎−3𝑏)𝑐 = 2𝑎^2−3𝑏^2+𝑎𝑐+𝑏𝑐−𝑎𝑏−(2𝑎𝑐−3𝑏𝑐) = 2𝑎^2−3𝑏^2+𝑎𝑐+𝑏𝑐−𝑎𝑏−2𝑎𝑐+3𝑏𝑐 = 2𝑎^2−3𝑏^2−𝑎𝑏+(𝑎𝑐−2𝑎𝑐)+(𝑏𝑐+3𝑏𝑐) = 𝟐𝒂^𝟐−𝟑𝒃^𝟐−𝒂𝒃−𝒂𝒄+𝟒𝒃𝒄

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.