中等MATH-EXAM-011
Which working is the safest way to handle a negative divisor in an inequality?
A. Write the division step and reverse the inequality symbol✓ 答案
B. Reverse the symbol at every step, whether or not the divisor is negative
C. Drop the negative sign and keep the symbol
D. Replace the variable by its absolute value
解說
The symbol reverses only when you multiply or divide by a negative number. Writing that step is the method mark. Reversing at every line, or deleting the minus sign, produces a different solution set.