X = 8.5 because 8.5 x 2 = 17 and 17 + 1 = 18
Answer: See below
Step-by-step explanation:
27. -(a-3)
28. (b-1)(b+3)
29. (c+4)(c+5)
30. d(d+5)
31. -(3/4)(2e-5)
Sorry - I don't have time to enter the details. Look for areas where the expressions can be factored in a manner that forms as many equivalent expressions in both the numerator and denominator.
For example: In problem 30:
(5d-20)/(d^2+d-20) * [??]/20d = 1/4
Factor:
<u>(5(d-4))</u> <u>d(d+5)</u> = 1/4
(d-4)(d+5<u>)</u> 20d
The (d-4), d+5, and d terms cancel, leaving
5/20 = 1/4
First write out all the two digit square numbers
4² = 16
5² = 25
6² = 36
7² = 49
8² = 64
9² = 81
Next divide all of them by 7
16/7 = 2 2/7 or 2 and 2 remainders
25/7 = 3 4/7 or 3 and 4 remainders
36/7 = 5 1/7 or 5 and 1 remainder
49/7 = 7
64/7 = 9 1/7 or 9 and 1 remainder
81/7 = 11 4/7 or 11 and 4 remainders
This tells us that the only possible remainders for a two digit square number divided by 7 are 1, 2 and 4
If Doris got 6 and Horace got 3, they must have made a mistake.
Area of a circle = pi * r^2
Radius (r) = ½ * diameter
½ * 10 = 5
A= pi * 5^2
25 * pi = 78.54 sq inches
10.99 / 78.54 = about 14 cents per sq in (13.99)
