You simplify both sides and isolate the variable.
Answer:

Step-by-step explanation:
Fixed monthly fee = $20
Amount charged per minute for long distance calls = $0.20
denotes total cost such that
minutes are used for long distance calls.
Amount charged for
minutes for long distance calls 
Therefore, an equation for the total cost, C, when N minutes are used for long distance calls is 
Answer:
yes
Step-by-step explanation:
8² + 15² = 17²
64 + 225 = 289
289 = 289
Option D:
15c ≤ 200
Solution:
Let c be the number of cases of tea bags.
Cost of each tea bag = 15 gold coins
Total gold coins Mad have = 200
<u>Set up an inequality:</u>
Cost of c tea bags = 15 × c = 15c
Mad can buy tea bags at most 200 gold coins.
(At most 200 means 200 is the greater value)
15 × c ≤ 200
15c ≤ 200
Hence option D is the correct answer.
Answer:
33.33%
Step-by-step explanation:
We need to calculate the <u>unit selling price and cost of each cosmetics.</u>
If a person bought some cosmetics from wholesale market at the rate of Rs 360 per dozen., then for 1 cosmetics, we will say;
x = 1 cosmetic
since 360 = 12 cosmetic
cross multiply
12x = 360
x = 360/12
x = 30
Hence the unit cost price of the cosmetics will be Rs. 30
Similarly, if he sells it at Rs 80 a pair, then he sold one cosmetic at 80/2 = Rs. 40 (a pair is 2 cosmetics)
Selling price per unit = Rs. 40
Cost price per unit = Rs. 30
percent gain = SP-CP/CP * 100%
percent gain = 40-30/30 * 100
percent gain = 10/30 * 100
percent gain = 100/3
percent gain = 33.33%
Hence the percentage gain is 33.33%