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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

Which two points are on the graph of y=x-4

Ann [662]

The answer is C because since the answer is 4 and if u look at c it would equal to 4.

8 0

3 years ago

Read 2 more answers

X+7y=0 X+4y=8 Solve the equation

RideAnS [48]

Answer:

1.x=-7y

2.x=8-4y

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

How many solutions does the equation 5x + 3x − 4 = 10 have? (4 points) Zero One Two Infinitely many

podryga [215]

Hey there!

Let's solve this equation.

5x+3x-4=10

add the x's

8x-4=10

add 4 to both sides

8x=10+4

8x=14

divide both sides by 8

x=14/8

Reduce the fraction;

x=7/4 (improper fraction)

x=1+3/4 (mixed number)

Hence, the equation has 1 solution.

Hope everything is clear.

Let me know if you have any questions!

#ILoveLearning

:-)

4 0

2 years ago

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Name the property used : fast i beg you a) -17 ×1 = -17 b) (-5) + 6 = 6 + (-5)

Sergeeva-Olga [200]

Answer:

a) identity property of multiplication

b) commutative property in addition

4 0

3 years ago