Question 9 - Mind the Mistake, Mend the Mistake - Chapter 6 Class 8 - We Distribute yet things Multiply (Ganita Prakash)

Transcript

Question 9 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 first part (2a3 + 3a3 = 5a3) was correct. But in the second part, they tried to add 6a2b and 6ab2. These are unlike terms because the powers are on different letters (a2 vs a1). Correct solution 2𝑎^3+3𝑎^3+6𝑎^2 𝑏+6〖𝑎𝑏〗^2 =(2𝑎^3+3𝑎^3 )+6𝑎^2 𝑏+6〖𝑎𝑏〗^2 =𝟓𝐚^𝟑+𝟔𝒂^𝟐 𝒃+𝟔〖𝒂𝒃〗^𝟐