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2 years ago

Solve by transforming into a perfect square trinomial x squared-14x=15

1 answer:

8 0

X^2 - 14 x = 15

(x - 7)^2 - 49 = 15

(x-7)^2 = 64

x - 7 = - or + 8

x = 15 or -1

Just take half o the coefficient of x and subtract it squared as above.

In general

x^2 + ax = b

(x + a/2)^2 - a^2/4 = b

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What is the 4th term of the sequence?

matrenka [14]

$\bf \begin{array}{ll}
term&value\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
a_1&8\\\\
a_2&6+a_{2-1}\\
&6+a_1\\
&6+8\\
&14\\\\
3&6+a_{3-1}\\
&6+a_2\\
&6+14\\
&20\\\\
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\end{array}$

4 0

2 years ago

What is the value of x in the equation <img src="https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B5%7Dx%20-%5Cfrac%7B2%7D%7B3%7D" id="Te

SVEN [57.7K]

Answer:

x= 200

Step-by-step explanation:

The given equation is:

1/5 x - 2/3 y = 30

The value of y is 15

Put the value of y in the given equation:

1/5 x - 2/3(15) = 30

1/5 x- 10 = 30

Take the L.C.M of the denominator

x-50/5 = 30

Move the denominator to the R.H.S

x-50 = 30*5

x-50 = 150

Combine the like terms

x= 150+50

x = 200

The value of x is 200...

5 0

3 years ago

Read 2 more answers

How do you find the circumference of a circle??

Phoenix [80]

Answer:

how do you find the circumference of a circle??

C=2πr

4 0

2 years ago

Read 2 more answers

10 POINTS !! :( ANSWER BOTH PLS !! DUE BEFORE 11:59 PM

fenix001 [56]

Answer:

Easy,

1) To find the area you need to multiply. Therefore 10 x 4 = 40 square centimeters.

2) 20, why? A calculator online for area of a triangle, it really helps! :) just look up triangle area in the future.

Step-by-step explanation:

8 0

2 years ago

In a certain country the life expectancy for women in 1990 was 45 and in 2000 it was 85?years. Assuming that life expectancy bet

Darya [45]

Answer:

49145 years

Step-by-step explanation:

In a certain country the life expectancy for women in 1990 was 45 and in 2000 it was 85?years.

Assuming that life expectancy between 2000 and 2100 increases by the same percentage as it did between 1900 and 2000,what will life expectancy be for women in 2100?

In 10 years, the expectancy increased by 85/45 = 17/9

between 2000 and 2100, it will increas by 10 time 10 years, so expected expectancy is $85*(\frac{85}{45})^{10} = 49145$ years

4 0

3 years ago