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3 years ago

What is the solution of the following quadratic inequality? x2 – 4x – 21 ≤ 0

Mathematics

2 answers:

Dominik [7]3 years ago

7 0

Answer:

3, and -7

Step-by-step explanation:

First factor the trinomial

y=x2−4x−21

Find 2 numbers knowing sum (-4) and product (c = - 21). They are the numbers in the factor pair (3, -7).

y = (x + 3)(x - 7)

Solving the 2 binomials, we get:

x = -3 and x = 7

trasher [3.6K]3 years ago

6 0

Answer: Its B

A number line going from negative 8 to 8. Closed circles are at negative 3 and 7. The line between the circles is shaded.

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Answer for x. 1. 3x - 10 = -21 2. -22 - 4x = 12

ra1l [238]

Answer:

3x - 10 = -21

add 10 on both side

3x-10+10=-21+10

3x=-11

divide both side by 3

3x/3=-11/3

x=-11/3

Step-by-step explanation:

2. -22 - 4x = 12

add 22 on both side

-22+22-4x=12+22

-4x=36

divide both side by -4

-4x/-4=36/-4

c=-9 is your answer

4 0

3 years ago

I was just wondering if this was right most likely not

MrRa [10]

Answer:

Yes you are correct :)

Step-by-step explanation:

Used a graphing calculator

4 0

3 years ago

Read 2 more answers

jack has $7.55 of change in his pocket. if he has 4 more dimes than than nickels, and twice as many quarters as nickels, how man

dolphi86 [110]

Answer:

11 nickels, 15 dimes, 22 quarters

Step-by-step explanation:

number of nickels = x

number of dimes = x+4

number of quarters = 2x

- - - - - -

total of nickels = 5x cents

total of dimes = 10x + 40 cents

total of quarters = 50x cents

- - - - - -

755 = 5x + 10x + 40 + 50x

755 = 65x + 40

715 = 65x

x = 11

x+4 = 15

2x = 22

8 0

3 years ago

3x+5y= 12 Solve For Y Anyone

Vsevolod [243]

3x+5y= 12
5y = 12 -3x
y = (12-3x)/5
y = 12/5 - 3x/5
y = 2.4 -0.6x
or
y = -0.6x + 2.4

8 0

3 years ago

Read 2 more answers

The cost of a ticket to the circus is $14.00 for children and $32.00 for adults. On a certain day, attendance at the circus was

Evgesh-ka [11]

400 children and 600 adults bought tickets.

Step-by-step explanation:

Given,

Cost of one child ticket = $14

Cost of one adult ticket = $32

Total attendance = 1000

Revenue generated = $24800

Let,

x be the number of children.

y be the number of adults.

According to given statement;

x+y=1000 Eqn 1

14x+32y=24800 Eqn 2

Multiplying Eqn 1 by 14

$14(x+y=1000)\\14x+14y=14000\ \ \ Eqn\ 3$

Subtracting Eqn 3 from Eqn 2

$(14x+32y)-(14x+14y)=24800-14000\\14x+32y-14x-14y=10800\\18y=10800\\$

Dividing both sides by 18

$\frac{18y}{18}=\frac{10800}{18}\\y=600$

Putting y=800 in Eqn 1

$x+600=1000\\x=1000-600\\x=400$

400 children and 600 adults bought tickets.

Keywords: linear equations, subtraction

Learn more about subtraction at:

#LearnwithBrainly

8 0

3 years ago