Question 1 - Mind the Mistake, Mend the Mistake - Chapter 6 Class 8 - We Distribute yet things Multiply (Ganita Prakash)

Transcript

Question 1 We have expanded and simplified some algebraic expressions below to their simplest forms. (i) Check each of the simplifications and see if there is a mistake. (ii) If there is a mistake, try to explain what could have gone wrong. (iii) Then write the correct expression.Is there a mistake? Yes What went wrong? The student treated the parentheses as addition or subtraction. In algebra, a number (or term) right next to a bracket means multiplication. We need to distribute the –3p to everything inside. Correct solution −3𝑝(−5𝑝+2𝑞) =(−𝟑𝒑)× (−𝟓𝒑)+(−𝟑𝒑) × (𝟐𝒒) =3 × 5 × 𝑝 × 𝑝−3 × 2 × 𝑝 × 𝑞 =𝟏𝟓𝒑^𝟐−𝟐𝒒