15 lbs equal to __

8 times of the eight term of an arithmetic progression is equal to 12 times of the twelfth term. find its first term if the comm

Ilya [14]

Answer:

a₁ = 38

Step-by-step explanation:

Given AP, where:

8a₈ = 12a₁₂
d = -2,
a₁ = ?

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<h3>Solution</h3>

aₙ = a₁ + (n-1)d

a₈ = a₁ + 7d = a₁ + 7*(-2) = a₁ - 14
a₁₂ = a₁ + 11d = a₁ + 11*(-2) = a₁ - 22

8a₈ = 12a₁₂

8(a₁ - 14) = 12(a₁ - 22)
2(a₁ - 14) = 3(a₁ - 22)
2a₁ - 28 = 3a₁ - 66
3a₁ - 2a₁ = -28 + 66
a₁ = 38

6 0

3 years ago

Rationalize the denominator of $\frac{5}{2+\sqrt{6}}$. The answer can be written as $\frac{A\sqrt{B}+C}{D}$, where $A$, $B$, $C$

horrorfan [7]

Answer:

$A +B+C+D = 3$ is the correct answer.

Step-by-step explanation:

Given:

$\frac{5}{2+\sqrt{6}}$

To find:

$A+B+C+D = ?$ if given term is written as following:

$\frac{A\sqrt{B}+C}{D}$

<u>Solution:</u>

We can see that the resulting expression does not contain anything under $\sqrt$ (square root) so we need to rationalize the denominator to remove the square root from denominator.

The rule to rationalize is:

Any term having square root term in the denominator, multiply and divide with the expression by changing the sign of square root term of the denominator.

Applying this rule to rationalize the given expression:

$\dfrac{5}{2+\sqrt{6}} \times \dfrac{2-\sqrt6}{2-\sqrt6}\\\Rightarrow \dfrac{5 \times (2-\sqrt6)}{(2+\sqrt{6}) \times (2-\sqrt6)} \\\Rightarrow \dfrac{10-5\sqrt6}{2^2-(\sqrt6)^2}\ \ \ \ \ (\because \bold{(a+b)(a-b)=a^2-b^2})\\\Rightarrow \dfrac{10-5\sqrt6}{4-6}\\\Rightarrow \dfrac{10-5\sqrt6}{-2}\\\Rightarrow \dfrac{-5\sqrt6+10}{-2}\\\Rightarrow \dfrac{5\sqrt6-10}{2}$

Comparing the above expression with:

$\frac{A\sqrt{B}+C}{D}$

A = 5, B = 6 (Not divisible by square of any prime)

C = -10

D = 2 (positive)

GCD of A, C and D is 1.

So, $A +B+C+D = 5+6-10+2 = \bold3$

5 0

3 years ago

Peyton's field hockey team wins 4 games out of every 7 games played. Her team lost 9 games. How many games did Peyton's team pla

andre [41]

Answer:

Games played= 21 games

Step-by-step explanation:

Giving the following information:

Peyton's field hockey team wins 4 games out of every 7 games played.

We know that Peyton's team loses 3 games out of 7.

So if the team lost 9 games, the proportion is completed 3 times.

Games played= 3*7= 21 games

4 0

3 years ago

Help find the missing segment???

SVEN [57.7K]

(9/6) = (15/?)
9? = 90
? = 10

6 0

2 years ago

Read 2 more answers

Plis reply fast and get brainless

insens350 [35]

Answer:

number 1 - 2 is bigger ----- Number 2 - 1 is bigger ------ Number three - 5 is bigger

Step-by-step explanation:

7 0

3 years ago

15 lbs equal to ___ kg