Answer:
$0.3
Step-by-step explanation:
8.90x2=17.8
1.75x2=3.5
17.8+3.5=21.3
21.90-21.3=0.6
0.6/2=0.3
Answer:

Step-by-step explanation:
The given sequence is 3,15,75,375,...
The first term of this geometric sequence is

The common ratio is

The explicit formula is given by:

We plug the first term and common ratio into the formula to get:

In this question, you're solving for d.
Solve for d:
5(-6 - 3d) = 3(8+7d)
Use the distributive property:
-30 - 15d = 3(8+7d)
-30 - 15d = 24 + 21d
Add 30 to both sides:
-15d = 54 + 21d
Subtract 21d from both sides
-36d = 54
Divide both sides by -36
d = -3/2
Answer:
d = -3/2 or -1.5
So to solve this you need to reverse factor this problem
x^2 + 8x + 7 = 0
The common formula is this for factoring ax^2 + bx + c
Now you have to think what multplties to "c" and adds up to "b".
So in this case it's 7 x 1 = 7 and 7 + 1 = 8
So you set it up like this
(x + 7)(x + 1) = 0
So now you can check the factors by multiplying them together and see if it gets your original equation which is does.
So finally to get the answers you need to set each parenthesis to 0 and solve for x.
x + 7 = 0
x + 1 = 0
and we get x = -1 and - 7
You can also plug these two answers back into your original equation to see if it equals 0.
If you have any questions please feel free to comment
Answer:
The number must be 30.
Step-by-step explanation:
The mystery number is less then 40.
You say its name when you start at 3 and count by 3s. This means that it is a multiple of 3.
You say its name when you start at 5 and count by 5s. This means that it is a multiple of 5.
The only two numbers that are multiples of 3 and 5 and less than 40 are 15 and 30.
Since we have been told that the number is not 15, the number must be 30.