31.

Solve each question using the quadratic formula? X2+4x+3=0

Sergeeva-Olga [200]

x=−1 or x=−3 i think lol

8 0

3 years ago

a television on sale for 1/4 off original price. Original price is 120 more then sale price. What is original price of tv

agasfer [191]

Answer:

Original Price = 160

Sale Price =40

Step-by-step explanation:

Let Original Price be x and Sale Price be y

y=1/4 of x (Equation 1)

x=120+y (Equation 2)

Put value of x from equation 2 in equation 1

y= (1/4)*(120+y)

y=120/4 + y/4

y-y/4=30

3y/4=30

y=30*4/3

y=40

Put value of y in Equation 2

x=120+40

x=160

4 0

3 years ago

A fish was swimming LaTeX: 2\frac{1}{2}2 1 2 feet below the water's surface at 1:00 p.M. Three hours later, the fish was at a de

marin [14]

Answer:

$\frac{23}{4}$ feet

Step-by-step explanation:

The depth of the fish to the surface of water at 1:00 pm = 2 $\frac{1}{2}$ feet

= $\frac{5}{2}$ feet

The depth of the fish to its initial position at 4:00 pm = 3 $\frac{1}{4}$ feet

= $\frac{13}{4}$ feet

The position of the fish with respect to the water's surface at 4:00 pm = the depth of the fish to the surface of water at 1:00 pm + the depth of the fish to its initial position at 4:00 pm

= $\frac{5}{2}$ + $\frac{13}{4}$

= $\frac{10 + 13}{4}$

= $\frac{23}{4}$

The position of the fish with respect to the water's surface at 4:00 pm is $\frac{23}{4}$ feet.

8 0

3 years ago

Find the number of triangles with c =7, b=11, and B=21 degrees

muminat

<h3>Answer:</h3>

1

<h3>Step-by-step explanation:</h3>

The given angle is opposite the longest given side, so there will be exactly one solution.

_____

The number of solutions may be 0, 1, or 2 when the given angle is opposite the shortest given side.

6 0

3 years ago

Find all roots: x^3 + 7x^2 + 12x = 0 Show all work and check your answer.

Aliun [14]

The three roots of x^3 + 7x^2 + 12x = 0 is 0,-3 and -4

Solution:

We have been given a cubic polynomial.

$x^{3}+7 x^{2}+12 x=0$

We need to find the three roots of the given polynomial.

Since it is a cubic polynomial, we can start by taking ‘x’ common from the equation.

This gives us:

$x^{3}+7 x^{2}+12 x=0$

$x\left(x^{2}+7 x+12\right)=0$ ----- eqn 1

So, from the above eq1 we can find the first root of the polynomial, which will be:

x = 0

Now, we need to find the remaining two roots which are taken from the remaining part of the equation which is:

$x^{2}+7 x+12=0$

we have to use the quadratic equation to solve this polynomial. The quadratic formula is:

$x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$

Now, a = 1, b = 7 and c = 12

By substituting the values of a,b and c in the quadratic equation we get;

$\begin{array}{l}{x=\frac{-7 \pm \sqrt{7^{2}-4 \times 1 \times 12}}{2 \times 1}} \\\\{x=\frac{-7 \pm \sqrt{1}}{2}}\end{array}$

Therefore, the two roots are:

$\begin{array}{l}{x=\frac{-7+\sqrt{1}}{2}=\frac{-7+1}{2}=\frac{-6}{2}} \\\\ {x=-3}\end{array}$

And,

$\begin{array}{c}{x=\frac{-7-\sqrt{1}}{2}} \\\\ {x=-4}\end{array}$

Hence, the three roots of the given cubic polynomial is 0, -3 and -4

4 0

3 years ago