<u>Answer</u>
c. buying it at a 10 percent discount without sales tax.
<u>Explanation</u>
We are going to compare the 3 choices and then determine the most cost effective.
<em>a. using a paid membership card to buy it at a 10 percent discount.</em>
10% of $100 = 10/100×100 = $10
cost = $100 - $10 = $90
On top of this $90 there is the charges of the membership card.
<em> b. buying it online at a 10 percent discount with a $5 shipping charge.</em>
100%-10% = 90%
90% of 100 = $90
Cost: $90 + $5 = $95
<em>c. buying it at a 10 percent discount without sales tax.</em>
100% - 10% = 90%
90/100 × 100 = $90. This is the must cost effective method since there is no other cost involved.
39 it's an arithmetic sequence in which the common difference is +7
Answer:
x = -8
Step-by-step explanation:
Let's put this into numbers: 
x =-6
The first thing you want to do is to multiply both sides by 4:
3x=-24
Next you need to divide by 3:
x=-8
The answer is -8
√7 is not a perfect square , so it's irrational
Answer is B. irrational numbers
P.S .
Keep in mind that any of non perfect square is irrational
