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3 years ago

Solve this equation using an algebraic method: (x + 4)( x - 4) = 9

2 answers:

5 0

Use FOIL method first to get rid of ()
x^2 - 4x + 4x -16 = 9
x^2 - 16 = 9
move the 16 over by addition
x^2 = 25
Then take the square root and get
x = 5

Luden [163]3 years ago

3 0

Perform indicated operations on left side

x*x+4x+4x+4*4=9

x^2+4x+4x+16=9 combine like terms on left side

x^2+8x+16=9 subtract 9 from both sides

x^2+8x+7=0 factor

x^2+x+7x+7=0

x(x+1)+7(x+1)=0

(x+7)(x+1)=0

x=-1, -7

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Solve the given equation by completing the square.

Dmitriy789 [7]

Answer:

a = -4, b = 3 and c = 6 (OR)

a = -4, b = -3 and c = 6

Step-by-step explanation:

$x^{2} +8x = 38$

Add 16 to both sides.

$x^{2} +8x+16 = 38 + 16$

$(x+4)^{2} =54$

$x + 4 = \sqrt{54}$ or $x + 4 = -\sqrt{54}$

$x+4=3\sqrt{6}$ or $x+4=-3\sqrt{6}$

$x=-4+3\sqrt{6}$ or $x=-4-3\sqrt{6}$

Therefore, a = -4, b = 3 and c = 6 (OR)

a = -4, b = -3 and c = 6

6 0

3 years ago

Read 2 more answers

A teacher writes a simple computer program where she can type students name and computer tells her the students birthday.

Vikki [24]

Considering that each student has only one birthday, each input will be related to only one output, hence this relation is a function.

<h3>When does a relation represent a function?</h3>

A relation represents a function when each value of the input is mapped to only one value of the output.

For this problem, we have that:

The input is the student's name.

The output is the student's birthday.

Each student has only one birthday, hence each input will be related to only one output, hence this relation is a function.

More can be learned about relations and functions at brainly.com/question/12463448

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5 0

1 year ago

Can someone pls pls help me ?

Yakvenalex [24]

9514 1404 393

Answer:

a = 9 meters

Step-by-step explanation:

The perimeter is the sum of the side lengths:

28 m = a + 2m + a + 8m

18 m = 2a . . . . . . . . . . . . . . . . subtract 10m, collect terms

9 m = a . . . . . . . . . . . . . . . divide by 2

The value of a is 9 meters.

8 0

2 years ago

Two semicircles are attached to the sides of a rectangle as shown.

melomori [17]

Answer:

$157\ in^{2}$

Step-by-step explanation:

we know that

The area of the figure is equal to the area of rectangle plus the area of two semicircles

<u>The area of rectangle is equal to</u>

$A=14*5=70\ in^{2}$

<u>The area of the small semicircle is equal to</u>

$A=\pi r^{2} /2$

$r=5/2=2.5\ in$ -----> radius is half the diameter

substitute

$A=(3.14)(2.5^{2})/2=9.8125 in^{2}$

<u>The area of the larger semicircle is equal to</u>

$A=\pi r^{2} /2$

$r=14/2=7\ in$ -----> radius is half the diameter

substitute

$A=(3.14)(7^{2})/2=76.93\ in^{2}$

The area of the figure is equal to

$70+9.8125+76.93=156.7425=157\ in^{2}$

8 0

3 years ago

Read 2 more answers

What is the value of X?

joja [24]

Answer:

27 is ta value of x because.. first of all add allthose threee sides

3(x+2)+ 35+ 52=180(the sum of triangle)

or, 3x+6+35+52=180

or,3x=180-93

or,x=87/3

Therefore, the value of x is 29

Step-by-step explanation:

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4 0

1 year ago