What is the missing reason in the proof?

Factor the quadratic equation below to reveal the solutions. X^2+4x-21=-9

a_sh-v [17]

Answer:

x = 3 and x = -7

Step-by-step explanation:

The given quadratic equation is $x^2+4x-21=0$ . We need to find the solution of this equation.

If the equation is in the form of $ax^2+bx+c=0$ , then its solutions are given by :

$x=\dfrac{-b\pm \sqrt{b^2-4ac} }{2a}$

Here, a = 1, b = 4 and c = -21

Plugging all the values in the value of x, such that :

$x=\dfrac{-b+ \sqrt{b^2-4ac} }{2a},\dfrac{-b- \sqrt{b^2-4ac} }{2a}\\\\x=\dfrac{-4+ \sqrt{(4)^2-4\times 1\times (-21)} }{2(1)},\dfrac{-4- \sqrt{(4)^2-4\times 1\times (-21)} }{2(1)}\\\\x=3, -7$

So, the solutions of the quadratic equation are 3 and -7.

6 0

3 years ago

Plz help fifty points

likoan [24]

Answer:

for question 13

130
50
50
130
130
50
50
130

Step-by-step explanation:

for 14

x. 150

y. 15

z. 150

i cant say that this is totally correct but im taking a educated guess

7 0

2 years ago

Read 2 more answers

Shown below is a blueprint for a rectangular kennel at a pet hotel.

yulyashka [42]

Answer:

The total length of fencing needed to enclose the kennel 74 feet.

Step-by-step explanation:

Given:

The blueprint of the rectangular kennel shows one side is 23 feet and another side is 14 feet.

As it is a rectangular shape, let the two sides be the length and the breadth of the rectangular kennel. i.e

$length = L = 23\ feet\\breadth = B = 14\ feet\\$

To find:

Total length of fencing needed is to enclose the kennel. i.e

Perimeter of a rectangular kennel = ?

Solution:

we have the formula for perimeter of a rectangle as giving below.

$\textrm{perimeter of rectangle} = 2(length + breadth) \\\textrm{total length of fencing} = 2( L+B)\\ \textrm{substituting the values of length and breadth we get}\\ \textrm{total length of fencing} = 2(23+14)\\=2\times37\\= 74\ feet$

Therefore,the total length of fencing needed to enclose the kennel 74 feet.

8 0

3 years ago

Find the value of X 90 58 122 32 <br> PLEASE ANSWER NOWW<br> 20pts

Viktor [21]

Answer:

58

Step-by-step explanation:

The two angles are equal

5 0

3 years ago

Read 2 more answers

The value of the correlation coefficient is always in the range<br> a. 0 to 1 b. 1 to 1 c. 1 to 0

dlinn [17]

Answer:

-1 to 1

Step-by-step explanation:

The correlation Coefficient gives the degree of relationship between two variables while also giving an hint about the type of relationship between them, (positive or negative). Correlation Coefficient could take any value bwuqwen - 1 and 1. With values closer to - 1 or 1 indicating a strong relationship between the variables, Coefficient of 0 means no relationship and a negative value means negative relationship while a positive value plies a positive relationship.

7 0

3 years ago