Algebra Demystified 2nd Ed

320 algebra De mystif ieD

✔SOLUTIONS

1. x ≥ 5 [5, Ç)


2. x < 1 (–Ç, 1)


3. x ≤ 4 (–Ç, 4]


4. x ≥ –10 [–10, Ç)


5. x ≤ –2 (Ç, –2]


6. x > 9 (9, Ç)


7. x < –8 (–Ç, –8)


8. x > ^1
   2

1

2

 , ∞∞







Applied Problems

We use linear inequalities to solve applied problems in much the same way that

we used linear equations to solve problems. There are two important differ-

ences, though. Multiplying and dividing both sides of an inequality requires that

the sign reverse. We must also decide which inequality sign to use: <, >, <, and >.

Tables 9-2 and 9-3 should help.

TABLE 92

A < B A > B

A is less than B A is greater than B

A is smaller than B A is larger than B

B is greater than A B is less than A

B is larger than A A is more than B

TABLE 93

A ≤ B B ≤ A

A is less than or equal to B B is less than or equal to A

A is not more than B B is not more than A

B is at least A A is at least B

B is A or more A is B or more

A is no greater than B B is no greater than A

B is no less than A A is no less than B