Grades 11-12 Video Solutions 2022-2022_11-12

Video Transcription

Video Summary

The problem involves determining the sign of two expressions: \(-2a^4b^3c^2\) and \(3a^3b^5c^{-4}\), given that they have the same sign. The key insight is that even powers do not affect the sign, so these can be ignored. For the first expression, ignoring even powers, its sign reduces to \(-b\). For the second expression, simplifying under the same principle, its sign reduces to \(ab\). Thus, \(-b\) and \(ab\) must have the same sign, implying that \(a\) must be negative. Therefore, the correct answer is that \(a\) is definitely negative.

Keywords

expression sign

even powers

negative a

simplifying expressions

same sign