Simplify the following expression.
$(2a - b - 3c)(4a^2 + b^2 + 9c^2 + 2ab + 6ac - 3bc )$
Answer & explanation
Correct answer: option 3
Given,
(2a - b - 3c)(4a2 + b2 + 9c2 + 2ab + 6ac - 3bc)
= 8a3+2ab2+18ac2+4a2b+12a2c−6abc−4a2b−b3−9bc2−2ab2−6abc+3b2c−12a2c−3b2c−27c3−6abc−18ac2+9bc2
= 8a3−18abc−b3−27c3
So the value of (2a - b - 3c)(4a2 + b2 + 9c2 + 2ab + 6ac - 3bc) = 8a3−18abc−b3−27c3