Ex 8.4, 1 (iii) - Chapter 8 Class 8 Algebraic Expressions and Identities

Last updated at August 13, 2026 by

Ex 8.4, 1 (iii) - Multiply the binomials (2.5𝑙 – 0.5𝑚) and (2.5𝑙 + - Ex 8.4

Remove Ads
Teachoo · Class 8 Explore Class 8

Transcript

Ex 8.4, 1 Multiply the binomials. (iii) (2.5𝑙 – 0.5𝑚) and (2.5𝑙 + 0.5𝑚) (2.5𝑙 – 0.5𝑚)(2.5𝑙 + 0.5𝑚) = 2.5𝑙(2.5𝑙+0.5𝑚)−0.5𝑚(2.5𝑙+0.5𝑚) = (2.5𝑙 × 2.5𝑙)+(2.5𝑙 × 0.5𝑚)−(0.5𝑚 × 2.5𝑙)−(0.5𝑚 × 0.5𝑚) = (𝟐𝟓𝒍/𝟏𝟎×𝟐𝟓𝒍/𝟏𝟎)+(𝟐𝟓𝒍/𝟏𝟎×𝟓𝒎/𝟏𝟎)−(𝟓𝒎/𝟏𝟎×𝟐𝟓𝒍/𝟏𝟎)−(𝟓𝒎/𝟏𝟎×𝟓𝒎𝒍/𝟏𝟎) = 625/100×(𝑙 × 𝑙)+125/100 (𝑙 × 𝑚)−(125/100)×(𝑚 × 𝑙)−(25/100)×(𝑚 × 𝑚) = 6.25𝑙^2+1.25𝑙𝑚−1.25𝑙𝑚−0.25𝑚^2 = 𝟔.𝟐𝟓𝒍^𝟐−𝟎.𝟐𝟓𝒎^𝟐

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh is an IIT Kanpur graduate and has been teaching for 16+ years. At Teachoo, he breaks down Maths, Science and Computer Science into simple steps so students understand concepts deeply and score with confidence.

Many students prefer Teachoo Black for a smooth, ad-free learning experience.