All categories

2 years ago

Solve using the Quadratic Formula:

Mathematics

1 answer:

Advocard [28]2 years ago

6 0

A. - 7x² + 7x + 1 + 8 = 0

- 7x² + 7x + 9 = 0

x = - b ± √b² - 4ac / 2a

= - 7 ± √7² - 4 (-7) (9) / 2 (-7)

= - 7 ± √49 + 252 / - 14

= - 7 ± √ 301 / - 14

x = - 7 + 17.349 / - 14 x = - 7 - 17.349 / - 14

= 10.349 / - 14 = - 24.349 / - 14

= - 0.739 = - 1.739

B. 8x² - 5x² + 6x + 1 = 0

3x² + 6x + 1 = 0

x = - b ± √b² - 4ac / 2a

= - (-5) ± √-5² - 4 (3) (1) / 2 (3)

= 5 ± √25 - 12 / 6

= 5 ± √ 13 / 6

x = 5 + 3.606 /6 x = - 5 - 3.606 / 6

= 8.606/6 = - 8.606/6

= 1.434. = - 1.434

please re-check the answers hope this helps

You might be interested in

9. Alicia Martin's savings account has a principle of $1,200. It earns 6% interest compounded quartly

zavuch27 [327]

Answer:

$9) \$1236.27\,10)\,\$6451.07\, 11)\,\$10,152.87 \,12)\,\$907.95 \,13)\,\$4957.69$

Step-by-step explanation:

9) Since Alicia Martin's savings earns 6% quarterly for two quarters then:

$A=P(1+\frac{r}{n})^{nt}$ ⇒ Amount (A), Principle (P), rate (r) in decimal form, number of compoundings (n) a year and t, in year or its fractions.

$A=P(1+\frac{r}{n})^{nt}\Rightarrow A=1200(1+\frac{0.06}{4})^{4*\frac{1}{2}}\Rightarrow A=\$1236.27$

10) Aubrey Daniel's case:

$A=P(1+\frac{r}{n})^{nt}\Rightarrow A=5725(1+\frac{0.04}{4})^{4*3}\Rightarrow A\approx \$6451.07$

11) As for Angelo, similarly to Alicia.

$A=P(1+\frac{r}{n})^{nt}\Rightarrow A=9855(1+\frac{0.06}{4})^{4*\frac{1}{2}}\Rightarrow A\approx \$10,152.87$

12) Simpson's. For semiannual n=2

$A=P(1+\frac{r}{n})^{nt}\Rightarrow A=860(1+\frac{0.055}{2})^{2*1}\Rightarrow A\approx \$907.95$

13) Jana Lacey amount:

$A=P(1+\frac{r}{n})^{nt}\Rightarrow A=4860(1+\frac{0.04}{4})^{4*\frac{1}{2}}\Rightarrow A\approx \$4957.69$

6 0

3 years ago

Question 6

marin [14]

Answer:

18 miles per hour is an outlier

the outlier decreases the mean speed

Step-by-step explanation:

the low number of 18 is way different from the other numbers being in the 30's and 40's

this 18 will bring the mean of all the numbers own because it is a smaller number.

8 0

3 years ago

Please help me with this geometry problem. :)

Reika [66]

Answer:

See below

Step-by-step explanation:

3 are congruent, 4 are supplementary

No matter which angle you pick you will get the same answer.

6 0

3 years ago

How many three-letter "words" can be made from 9 letters "fghijklmn" if repetition of letters (a) is allowed?

11Alexandr11 [23.1K]

729. You just do 9 to the power of 3 or 9^3 and you will get 729. If it is not allowed, the answer is 504.(9 x 8 x 7)

8 0

3 years ago

What is the completely factored form of f(x)=x3+5x2+4x−6?

Gre4nikov [31]

$f(x)=x^3+5x^2+4x-6$
$f(-3)=(-3)^3+5(-3)^2+4(-3)-6=0\implies x+3\text{ is a factor of }f(x)$

Synthetic division yields

-3 | 1   5   4   -6
.    |      -3 -6    6
- - - - - - - - - - - - -
.    | 1   2 -2    0

which translates to

$\dfrac{x^3+5x^2+4x-6}{x+3}=x^2+2x-2$

with remainder 0. Now by the quadratic formula,

$x^2+2x-2=0\implies x=\dfrac{-2\pm\sqrt{2^2-4(1)(-2)}}2=-1\pm\sqrt3$

and so

$f(x)=x^3+5x^2+4x-6=(x+3)(x-(-1+\sqrt3))(x-(-1-\sqrt3))$

3 0

3 years ago