No.140 Multiplying and Dividing by Negative Numbers
POINT
When multiplying or dividing both sides of an inequality by a negative number, reverse the inequality sign.
Example
Solve the following inequalities.
1
\(-3x<12\)
\(x>-4\)
2
\(-\frac{x}{2}\geq3\)
\(x\leq-6\)
TRY
Solve the following inequalities.
TRY 1
\(-5x<30\)
\(x>-6\)
TRY 2
\(-4x\geq20\)
\(x\leq-5\)
TRY 3
\(-\frac{x}{3}>4\)
\(x<-12\)
TRY 4
\(-\frac{x}{5}\leq2\)
\(x\geq-10\)
TRY 5
\(-7x>21\)
\(x<-3\)
TRY 6
\(-\frac{x}{6}\geq-2\)
\(x\leq12\)