work.

6. How many feet, board measure, in the flooring of a room 20 feet by
30 feet and 2½ inches thick?

7. Find value of x and y in the following equations:

2 x + 3 y = 33
4 x - y = 17.

8. Find value of x in equation x² - x - 40 = 170.

9. Find value of x in equation

--------
a / a² - x² x
- + / ------- = -
b \/ x² b

10. Explain the meaning of the expression a½ × b¾.

11. What is a logarithm?

12. What is the base of the common system?

13. In making what calculations are logarithms useful?

14. How do you find the logarithm of a number in a table of
logarithms?