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1 year ago

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Which shows the correct substitution of the values a, b, and c from the equation 0 = 4x2 + 2x – 1 into the quadratic formula bel

ow?
Quadratic formula: x = StartFraction negative b plus or minus StartRoot b squared minus 4 a c EndRoot Over 2 a EndFraction

2 answers:

neonofarm [45]1 year ago

8 0

Answer:

x = StartFraction negative 2 plus or minus StartRoot 2 squared minus 4(4)(negative 1) EndRoot Over 2(4) EndFraction

Step-by-step explanation:

we know that

The formula to solve a quadratic equation of the form

$ax^2+bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^2-4ac} }{2a}$

in this problem we have

$4x^2 + 2x - 1=0$

so

$a=4$

$b=2$

$c=-1$

substitute in the formula

$x=\frac{-2(+/-)\sqrt{2^2-4(4)(-1)} }{2(4)}$

therefore

x = StartFraction negative 2 plus or minus StartRoot 2 squared minus 4(4)(negative 1) EndRoot Over 2(4) EndFraction

Svet_ta [14]1 year ago

5 0

Answer:

Its a

Step-by-step explanation:

No need to read all that lol

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evan has a job selling magazine and newspaper subscriptions. he earns $23 for each magazine subscription and $54 for each newspa

SashulF [63]

First we write the variables already defined:
m = the number of magazine subscriptions sold
n = the number of newspaper subscriptions sold
We now write the system of inequations based on the following facts:
"he earns $ 23 for each magazine subscription and $ 54 for each newspaper subscription that he sells. his goal is to make more than $ 642 per week"
23m + 54n> 642
"I have expectations to sell at least 10 subscriptions per week"
m + n> = 10
Answer:
A system of inequalities that models the given situation is:
23m + 54n> 642
m + n> = 10

5 0

3 years ago

Solve the triangle. Round your answers to the nearest tenth. A. m∠A=43, m∠B=55, a=16 B. m∠A=48, m∠B=50, a=23 C. m∠A=48, m∠B=50,

alexgriva [62]

Answer:

D. m∠A=43, m∠B=55, a=20

Step-by-step explanation:

Given:

∆ABC,

m<C = 82°

AB = c = 29

AC = b = 24

Required:

m<A, m<C, and a (BC)

SOLUTION:

Find m<B using the law of sines:

$\frac{sin(B)}{b} = \frac{sin(C)}{c}$

$\frac{sin(B)}{24} = \frac{sin(82)}{29}$

$sin(B)*29 = sin(82)*24$

$\frac{sin(B)*29}{29} = \frac{sin(82)*24}{29}$

$sin(B) = \frac{sin(82)*24}{29}$

$sin(B) = 0.8195$

$B = sin^{-1}(0.8195)$

$B = 55.0$

m<B = 55°

Find m<A:

m<A = 180 - (82 + 55) => sum of angles in a triangle.

= 180 - 137

m<A = 43°

Find a using the law of sines:

$\frac{a}{sin(A)} = \frac{b}{sin(B)}$

$\frac{a}{sin(43)43} = \frac{24}{sin(55)}$

Cross multiply

$a*sin(55) = 25*sin(43)$

$a = \frac{25*sin(43)}{sin(53)}$

$a = 20$ (approximated)

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2 years ago

deenas water bottle can hold a total of 2/5 liter of water. johns water bottle can hold a total of 5/2 liter of water whose wate

Alexandra [31]

John's. Find the first common multiple of both denominators, in this case it's going to be ten, then the number you had to multiply to change these numbers to the common multiply you do to the numerators. so it works out like so:

Deena has a bottle of 4/10
John has a bottle of 25/10 or 2 1/2 (simplified)

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2 years ago

Read 2 more answers

If six girls can finish sweeping the floor of a hall in 45mins,how long will the same work take ten girls to do

AleksandrR [38]

Answer:

15 minutes i think

Step-by-step explanation:

45÷6=7.5

meaning 7.5 minutes per girl

so 4 girls would be 30 minutes of work

so 45-30=15

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2 years ago

. What is the value of x in the equation –6 + x = –2?

Usimov [2.4K]

4 is the right answer

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3 years ago