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2 years ago

Which quadratic equation has roots –2 and 1/5?

Mathematics

1 answer:

AysviL [449]2 years ago

4 0

Answer:

The equation $5x^2\:+\:9x\:-\:2\:=\:0$ has roots –2 and 1/5.

Hence, the option 'a' is the correct answer.

Step-by-step explanation:

Checking the equation

$5x^2\:+\:9x\:-\:2\:=\:0$

putting x = -2 in the equation

$5\left(-2\right)^2\:+\:9\left(-2\right)-\:2\:=\:0\:$

$2^2\cdot \:\:5-9\cdot \:\:2-2=0$

$2^2\cdot \:5-18-2=0$

$20-20=0$

$0=0$

L.H.S=R.H.S

putting x = 1/5 in the equation

$5\left(\frac{1}{5}\right)^2\:+\:9\left(\frac{1}{5}\right)-\:2\:=\:0\:$

$5\left(\frac{1}{5}\right)^2+9\cdot \:\frac{1}{5}-2=0$

$\frac{1}{5}+\frac{9}{5}-2=0$

$2-2=0$

$0=0$

L.H.S=R.H.S

As putting x = -2 and x = 1/5 satisfy the equation.

Therefore, the equation $5x^2\:+\:9x\:-\:2\:=\:0$ has roots –2 and 1/5.

Hence, the option 'a' is the correct answer.

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VashaNatasha [74]

Answer:

A. 4

Step-by-step explanation:

First, we can try the first option. 2/4 is equivalent to 6/12 when you multiply the fraction by 3 to get a common denominator. Since 6/12 is larger than 4/12, and the question has 1 answer, 4 is the only value that satisfices the statement and is the answer.

6 0

1 year ago

A landscape business charges $50 to deliver rocks. The cost of the rocks are $27 per cubic yard. write and solve a linear equati

Nuetrik [128]

<h2>Answer: 27x + 50 = y, $266</h2>

Step-by-step explanation:

First, let's form a linear equation that will help us find out how much that will cost.

Let's set x = the cubic yards of rocks delivered and y = total cost.

First, we know that the business charges 27 dollars for every x that you buy. That can be shown with a multiplication expression:

27x

Next, we know that the business charges a fixed fee of $50 for their services. This fee would be <em>added on</em> to the amount that they charge for the rocks that you buy.

That's our linear expression! Next, we need to find out the <em>total cost</em>, y, when you need 8 cubic yards of rocks delivered, x.

To solve this, we need to substitute values for at least one of our variables.

Since 8 describes the cubic yards of rocks delivered, we can substitute 8 for x.

But we don't know y, the total cost- that's what we're solving for! In other words, we're solving for y.

Let's just substitute in what we know:

27(8) + 50 = y.

216 + 50 = y

So, we know that it would cost $266 dollars to have 8 cubic yards of rocks delivered to a site.

By the way, you can also graph your linear equation to find the corresponding y-value to 8 as another way to solve your problem.

7 0

2 years ago

Find the missing angle.

hammer [34]

Answer:

Linear pair angle of 40 is

=180-40

=140

If, the two rays are parallel

Therefore, the two rays are parallel and the straight line is transversal

Therefore, (?) angle =140 corrosponding angle

Your answer is 140

4 0

2 years ago

What inequality matches the statement : A number is at most 40

Misha Larkins [42]

Answer:

N ( a number) $\leq$ 40

Step-by-step explanation:

Or just say

N $\leq$ 40

8 0

2 years ago

Read 2 more answers

4x^2 y+8xy'+y=x, y(1)= 9, y'(1)=25

jarptica [38.1K]

Answer with explanation:

$\rightarrow 4x^2y+8x y'+y=x\\\\\rightarrow 8xy'+y(1+4x^2)=x\\\\\rightarrow y'+y\times\frac{1+4x^2}{8x}=\frac{1}{8}$

--------------------------------------------------------Dividing both sides by 8 x

This Integration is of the form ⇒y'+p y=q,which is Linear differential equation.

Integrating Factor

$=e^{\int \frac{1+4x^2}{8x} dx}\\\\e^{\log x^{\frac{1}{8}+\frac{x^2}{2}}\\\\=x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}$

Multiplying both sides by Integrating Factor

$x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}\times [y'+y\times\frac{1+4x^2}{8x}]=\frac{1}{8}\times x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}\\\\ \text{Integrating both sides}\\\\y\times x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}=\frac{1}{8}\int {x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}} \, dx \\\\8y\times x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}=\int {x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}} \, dx\\\\8y\times x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}=-[x^{\frac{9}{8}}]\times\frac{ \Gamma(0.5625, -x^2)}{(-x^2)^{\frac{9}{16}}}\\\\8y\times x^{\frac{1}{8}}\times e^{\frac{x^2}{2}}=(-1)^{\frac{-1}{8}}[ \Gamma(0.5625, -x^2)]+C-----(1)$

When , x=1, gives , y=9.

Evaluate the value of C and substitute in the equation 1.

6 0

2 years ago