No.139 Basic Inequalities
POINT
Adding or subtracting the same number keeps the inequality sign unchanged. Multiplying or dividing both sides by a positive number also keeps its direction.
Example
Solve the following inequalities.
1
\(x+4<9\)
\(x<5\)
2
\(x-3\geq5\)
\(x\geq8\)
3
\(3x<15\)
\(x<5\)
4
\(\frac{x}{4}\geq3\)
\(x\geq12\)
TRY
Solve the following inequalities.
TRY 1
\(x+7<12\)
\(x<5\)
TRY 2
\(x-6>2\)
\(x>8\)
TRY 3
\(x+3\leq10\)
\(x\leq7\)
TRY 4
\(5x<30\)
\(x<6\)
TRY 5
\(\frac{x}{3}>4\)
\(x>12\)
TRY 6
\(\frac{x}{6}\geq-2\)
\(x\geq-12\)