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2 years ago

6

Rewrite the equation by completing the square x^2-14x+49=0

1 answer:

Karolina [17]2 years ago

8 0

Answer:

Here is the ans ...hope it helps:)

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What is the solution of y= 1/2x - 1 and y=3x+4

exis [7]

Answer:

(-2,-2)

Step-by-step explanation:

solve by elimination

3 0

3 years ago

I need help im confuse

Romashka [77]

Answer:

B. 12b $\leq$ 17

Step-by-step explanation:

< means less than

> means greater than

$\leq$ means less than or equal to

$\geq$ means greater than or equal to.

hope this helps.

4 0

3 years ago

Determine all intervals on which f(x) > 0.

8_murik_8 [283]

Answer: [-7, -4]u[0, 3]

4 0

3 years ago

The sum of two terms of gp is 6 and that of first four terms is 15/2.Find the sum of first six terms.

Gnoma [55]

Given:

The sum of two terms of GP is 6 and that of first four terms is $\dfrac{15}{2}.$

To find:

The sum of first six terms.

Solution:

We have,

$S_2=6$

$S_4=\dfrac{15}{2}$

Sum of first n terms of a GP is

$S_n=\dfrac{a(1-r^n)}{1-r}$ ...(i)

Putting n=2, we get

$S_2=\dfrac{a(1-r^2)}{1-r}$

$6=\dfrac{a(1-r)(1+r)}{1-r}$

$6=a(1+r)$ ...(ii)

Putting n=4, we get

$S_4=\dfrac{a(1-r^4)}{1-r}$

$\dfrac{15}{2}=\dfrac{a(1-r^2)(1+r^2)}{1-r}$

$\dfrac{15}{2}=\dfrac{a(1+r)(1-r)(1+r^2)}{1-r}$

$\dfrac{15}{2}=6(1+r^2)$ (Using (ii))

Divide both sides by 6.

$\dfrac{15}{12}=(1+r^2)$

$\dfrac{5}{4}-1=r^2$

$\dfrac{5-4}{4}=r^2$

$\dfrac{1}{4}=r^2$

Taking square root on both sides, we get

$\pm \sqrt{\dfrac{1}{4}}=r$

$\pm \dfrac{1}{2}=r$

$\pm 0.5=r$

Case 1: If r is positive, then using (ii) we get

$6=a(1+0.5)$

$6=a(1.5)$

$\dfrac{6}{1.5}=a$

$4=a$

The sum of first 6 terms is

$S_6=\dfrac{4(1-(0.5)^6)}{(1-0.5)}$

$S_6=\dfrac{4(1-0.015625)}{0.5}$

$S_6=8(0.984375)$

$S_6=7.875$

Case 2: If r is negative, then using (ii) we get

$6=a(1-0.5)$

$6=a(0.5)$

$\dfrac{6}{0.5}=a$

$12=a$

The sum of first 6 terms is

$S_6=\dfrac{12(1-(-0.5)^6)}{(1+0.5)}$

$S_6=\dfrac{12(1-0.015625)}{1.5}$

$S_6=8(0.984375)$

$S_6=7.875$

Therefore, the sum of the first six terms is 7.875.

5 0

3 years ago

Find the inverse of f(x)=(x−5)/(−4x−2)

uysha [10]

Answer:

${f}^{ - 1} (x)= \frac{ 5 - 2x }{ 4x + 1}$

Step-by-step explanation:

The given rational function is

$f(x) = \frac{x - 5}{ - 4x - 2}$

Let

$y = \frac{x - 5}{ - 4x - 2}$

Interchange x and y

$x= \frac{y- 5}{ - 4y - 2}$

Cross multiply

$x( - 4y - 2)= y- 5$

Expand

$- 4xy - 2x= y- 5 \\ - 4xy - y= 2x - 5 \\y( - 4x - 1)= 2x - 5$

Solve for y;

$y= \frac{ 2x - 5}{ - 4x - 1}$

or

$y= \frac{ 5 - 2x }{ 4x + 1}$

Therefore

${f}^{ - 1} (x)= \frac{ 5 - 2x }{ 4x + 1}$

7 0

3 years ago