Answer to 3x-y=2<br> -2x+4y=2

The difference between the two roots of the equation 3x^2+10x+c=0 is 4 2/3 . Find the solutions for the equation.

andrezito [222]

Answer:

Given the equation: $3x^2+10x+c =0$

A quadratic equation is in the form: $ax^2+bx+c = 0$ where a, b ,c are the coefficient and a≠0 then the solution is given by :

$x_{1,2} = \frac{-b\pm \sqrt{b^2-4ac}}{2a}$ ......[1]

On comparing with given equation we get;

a =3 , b = 10

then, substitute these in equation [1] to solve for c;

$x_{1,2} = \frac{-10\pm \sqrt{10^2-4\cdot 3 \cdot c}}{2 \cdot 3}$

Simplify:

$x_{1,2} = \frac{-10\pm \sqrt{100- 12c}}{6}$

Also, it is given that the difference of two roots of the given equation is $4\frac{2}{3} = \frac{14}{3}$

i.e,

$x_1 -x_2 = \frac{14}{3}$

Here,

$x_1 = \frac{-10 + \sqrt{100- 12c}}{6}$ , ......[2]

$x_2= \frac{-10 - \sqrt{100- 12c}}{6}$ .....[3]

then;

$\frac{-10 + \sqrt{100- 12c}}{6} - (\frac{-10 + \sqrt{100- 12c}}{6}) = \frac{14}{3}$

simplify:

$\frac{2 \sqrt{100- 12c} }{6} = \frac{14}{3}$

or

$\sqrt{100- 12c} = 14$

Squaring both sides we get;

$100-12c = 196$

Subtract 100 from both sides, we get

$100-12c -100= 196-100$

Simplify:

-12c = -96

Divide both sides by -12 we get;

c = 8

Substitute the value of c in equation [2] and [3]; to solve $x_1 , x_2$

$x_1 = \frac{-10 + \sqrt{100- 12\cdot 8}}{6}$

or

$x_1 = \frac{-10 + \sqrt{100- 96}}{6}$ or

$x_1 = \frac{-10 + \sqrt{4}}{6}$

Simplify:

$x_1 = \frac{-4}{3}$

Now, to solve for $x_2$ ;

$x_2 = \frac{-10 - \sqrt{100- 12\cdot 8}}{6}$

or

$x_2 = \frac{-10 - \sqrt{100- 96}}{6}$ or

$x_2 = \frac{-10 - \sqrt{4}}{6}$

Simplify:

$x_2 = -2$

therefore, the solution for the given equation is: $-\frac{4}{3}$ and -2.

3 0

2 years ago

Help with 4 and 5 please!!

Ghella [55]

Question 4
The magnitude;
Using Pythagoras theorem,
(-200)² + (-530)² = 320900
Length = √320900
= 566.5 mi
To get the angle
Tan θ = opposite/adjacent
= 200/530
= 0.3774
θ = tan^-1 (0.3774)
= 20.67
≈ 21°
The direction from the Cartesian plane is south of west.
Therefore, the magnitude and the direction will be;
About 566.5 mi, 21° south of west

Question 5.
To get the resultant of two vectors we just add the two vectors given.
This involves adding the corresponding values.
Thus, for <-6,5> and <6,-5>
Resultant vector = <(-6+6),(5+-5>
= <0,0>

4 0

3 years ago

the distance between Columbus Ohio and New York City is about 560 miles how many hours would it take the train to travel between

arlik [135]

How fast is the train going??

7 0

3 years ago

Read 2 more answers

What is the domain and range and function ??? Then can u explain how u did it please and thank you

enot [183]

The domain is
$- 10 \leqslant x \leqslant 10$
and the range is
$- 5 \leqslant y \leqslant 5$
Domain is x values (horizontal axis), while range is y values (vertical axis). On a line like this one, domain is calculated from the left most point to the right most, while range is calculated from the down most to the upmost.
Because this line is a solid line rather than a dotted line, less than or equal to
$\leqslant$
signs are used rather than just
$<$
less than signs.

6 0

3 years ago

What is the first step I’m solving for the variable?<br> 3(3x-7)=24

spin [16.1K]

Answer:

x = 5

Step-by-step explanation:

First you distribute

9x - 21 = 24

Add 21 to both sides

9x = 45

Divide both sides by 9

x = 5

4 0

2 years ago

Answer to 3x-y=2 -2x+4y=2