Find the errors and correct the following mathematical sentence:(3a +

1.	Find the errors and correct the following mathematical sentence:(3a + 4b)(a – b)= 3a2 – 4a2
Answer» (3a + 4b)(a – b) = 3a² – 4a² 3a(a – b) + 4b(a – b) = 3a² – 4a² 3a² – 3ab + 4ab – 4b² = – a² 3a² + ab – 4b² ≠ a² ∴ The given sentence is wrong. Correct sentence is (3a + 4b) (a – b) = 3a² + ab – 4b²

Find the errors and correct the following mathematical sentence:(3a + 4b)(a – b)= 3a2 – 4a2

Answer»

(3a + 4b)(a – b) = 3a² – 4a²

3a(a – b) + 4b(a – b) = 3a² – 4a²

3a² – 3ab + 4ab – 4b² = – a²

3a² + ab – 4b² ≠ a²

∴ The given sentence is wrong.

Correct sentence is (3a + 4b) (a – b) = 3a² + ab – 4b²