G
The circumference of a circle is π times diameter, so a circumference of hπ means a diameter of h. The radius is half the
diameter, or. Plug into the area formula:
20.
D
Just plug into the expression that defines the symbol ‡:
Note that at two points in your calculation, it is crucial to remember that subtracting a negative is the same as adding a
positive.
21.
J
Call the unknown number x. Then 5 less than three times the number, or 3 x − 5, equals twice the original number plus 7, or 2 x
+ 7. So 3 x − 5 = 2x + 7. Solve for x :
22.
D
All you need to do is plug the value of r = 3 into the formula you’re given and simplify:
23.
J
If you have trouble keeping track of the variable, try Picking Numbers. Think about each part of the programmer’s salary, then
put it together. She gets $100 a day for showing up. She gets $.05 per line of code, so if she writes n lines, she earns $.05n.
So her total salary is 100 + .05n dollars.
24.
25. E
