Ask question

Ask question

All categories

3 years ago

6

Please help me I don’t understand anything and I will give you thanks and points and give yo the brainliest

1 answer:

lana66690 [7]3 years ago

7 0

C....
B....
A....
D....

You might be interested in

SOMEONE HELP ME PLEASE AND THANK YOU!!!!! :D :"(

Nostrana [21]

Answer:

what are the drop down words.

6 0

2 years ago

Please help solve these proofs asap!!!

timama [110]

Answer:

Proofs contained within the explanation.

Step-by-step explanation:

These induction proofs will consist of a base case, assumption of the equation holding for a certain unknown natural number, and then proving it is true for the next natural number.

a)

Proof

Base case:

We want to shown the given equation is true for n=1:

The first term on left is 2 so when n=1 the sum of the left is 2.

Now what do we get for the right when n=1:

$\frac{1}{2}(1)(3(1)+1)$

$\frac{1}{2}(3+1)$

$\frac{1}{2}(4)$

$2$

So the equation holds for n=1 since this leads to the true equation 2=2:

We are going to assume the following equation holds for some integer k greater than or equal to 1:

$2+5+8+\cdots+(3k-1)=\frac{1}{2}k(3k+1)$

Given this assumption we want to show the following:

$2+5+8+\cdots+(3(k+1)-1)=\frac{1}{2}(k+1)(3(k+1)+1)$

Let's start with the left hand side:

$2+5+8+\cdots+(3(k+1)-1)$

$2+5+8+\cdots+(3k-1)+(3(k+1)-1)$

The first k terms we know have a sum of .5k(3k+1) by our assumption.

$\frac{1}{2}k(3k+1)+(3(k+1)-1)$

Distribute for the second term:

$\frac{1}{2}k(3k+1)+(3k+3-1)$

Combine terms in second term:

$\frac{1}{2}k(3k+1)+(3k+2)$

Factor out a half from both terms:

$\frac{1}{2}[k(3k+1)+2(3k+2]$

Distribute for both first and second term in the [ ].

$\frac{1}{2}[3k^2+k+6k+4]$

Combine like terms in the [ ].

$\frac{1}{2}[3k^2+7k+4$

The thing inside the [ ] is called a quadratic expression. It has a coefficient of 3 so we need to find two numbers that multiply to be ac (3*4) and add up to be b (7).

Those numbers would be 3 and 4 since

3(4)=12 and 3+4=7.

So we are going to factor by grouping now after substituting 7k for 3k+4k:

$\frac{1}{2}[3k^2+3k+4k+4]$

$\frac{1}{2}[3k(k+1)+4(k+1)]$

$\frac{1}{2}[(k+1)(3k+4)]$

$\frac{1}{2}(k+1)(3k+4)$

$\frac{1}{2}(k+1)(3(k+1)+1)$ .

Therefore for all integers n equal or greater than 1 the following equation holds:

$2+5+8+\cdots+(3n-1)=\frac{1}{2}n(3n+1)$

//

b)

Proof:

Base case: When n=1, the left hand side is 1.

The right hand at n=1 gives us:

$\frac{1}{4}(5^1-1)$

$\frac{1}{4}(5-1)$

$\frac{1}{4}(4)$

$1$

So both sides are 1 for n=1, therefore the equation holds for the base case, n=1.

We want to assume the following equation holds for some natural k:

$1+5+5^2+\cdots+5^{k-1}=\frac{1}{4}(5^k-1)$ .

We are going to use this assumption to show the following:

$1+5+5^2+\cdots+5^{(k+1)-1}=\frac{1}{4}(5^{k+1}-1)$

Let's start with the left side:

$1+5+5^2+\cdots+5^{(k+1)-1}$

$1+5+5^2+\cdots+5^{k-1}+5^{(k+1)-1}$

We know the sum of the first k terms is 1/4(5^k-1) given by our assumption:

$\frac{1}{4}(5^k-1)+5^{(k+1)-1}$

$\frac{1}{4}(5^k-1)+5^k$

Factor out the 1/4 from both of the two terms:

$\frac{1}{4}[(5^k-1)+4(5^k)]$

$\frac{1}{4}[5^k-1+4\cdot5^k]$

Combine the like terms inside the [ ]:

$\frac{1}{4}(5 \cdot 5^k-1)$

Apply law of exponents:

$\frac{1}{4}(5^{k+1}-1)$

Therefore the following equation holds for all natural n:

$1+5+5^2+\cdots+5^{n-1}=\frac{1}{4}(5^n-1)$ .

//

5 0

3 years ago

In the expression (x+y)^8, if x=0.3 and y=0.7 , what is the numerical value of the third term?

DanielleElmas [232]

Answer:

0.01000188

Step-by-step explanation:

The third term is ...

8C2·x^6·y^2 = 28 x^6 y^2

Putting in the given values for x and y, we get ...

28·3^6·7^2·10^-8 = 1000188×10^-8 = 0.01000188

_____

8C2 = 8!/(2!·(8-2)!) = 8·7/(2·1) = 28

3 0

3 years ago

Chloe spent $69 and now has no money left. She had before her purchase. She had $ before her purchase. can you please help me wi

max2010maxim [7]

Answer:

$69

Step-by-step explanation:

Given

$Purchase = \$69$

$Amount\ Left = \$0$

Required

Determine the cash before purchase

To get the her amount before the purchase, we simply add both given parameters together.

This is done as follows;

$Amount = Amount Left + Purchase$

Substitute 0 for Amount Left and 60 for Purchase

$Amount = \$0 + \$69$

$Amount = \$69$

<em>Hence, she had $69 before the purchase</em>

6 0

3 years ago

Làm giúp em câu 3+4 trắc nghiệm và bài 2+3 ạ

Alex777 [14]

Trắc nghiệm 3c, 4b
Tự luận 2a -48/5
2b x= 1/7
x=4/25

5 0

3 years ago