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3 years ago

X(x+9)(x-1)=72. find x

1 answer:

7 0

X(x+9)(x-1) = 72
lets expand the equation:
(x^2 + 9x)(x - 1) = 72
x^3 - x^2 + 9x^2 - 9x - 72 = 0
x^3 + 8x^2 - 9x - 72 = 0
and factorize again:
x^2(x + 8) - 9(x + 8) = 0
(x + 8)(x^2 - 9) = 0
that is:
(x + 8)(x + 3)(x - 3) = 0
double check that x^2 - 9 = (x + 3)(x - 3), that is a subtraction of squares easily factorizable:
So we have:
(x + 8)(x + 3)(x - 3) = 0
which solutions are:
x = -8, x = -3, x = 3

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The first 5 terms of a sequence are shown below:

nirvana33 [79]

Step-by-step explanation:

To find the formula for the nth term ,

First , find the common difference or common ratio.

Common difference =

$T_2-T_1 \\ - 2 - 3 \\ = - 5$

Common ratio =

$T_2/T_1 \\ \frac{ - 2}{3}$

The common difference applies to the other given numbers for example :

$T_3- T_2 = - 7 - ( - 2) \\ = - 7 + 2 = - 5$

this proves that it is an arithmetic sequence and the given formula for the nth term of an arithmetic sequence is

T_n =a(n-1)d

Where n = no of terms

a= first term

d= common difference

6 0

3 years ago

A more than 6 is -30 solve problem

erastovalidia [21]

Answer:

a = =36

Step-by-step explanation:

a + 6 = -30

make a on its own

a = -30 - 6

a = =36

8 0

3 years ago

Here are the vertices of rectangle FROG: (-2,5),(-2,1),(6,5),(6,1). Find the perimeter of this rectangle. If you get stuck, try

ryzh [129]

Answer:

Part 1) The perimeter of rectangle is equal to 24 units

Part 2) The area of rectangle is equal to 32 square units

Step-by-step explanation:

Part 1) Find the perimeter of rectangle

we know that

The perimeter of rectangle is equal to

$P=2(L+W)$

where

L is the length of rectangle

W is the width of rectangle

we have

$F(-2,5),R(-2,1),O(6,1),G(6,5)$

Plot the figure to better understand the problem

using a graphing tool

see the attached figure

Remember that in a rectangle opposite sides are congruent and the measure of each interior angle is equal to 90 degrees

$FG=RO=L\\RF=OG=W$

the formula to calculate the distance between two points is equal to

$d=\sqrt{(y2-y1)^{2}+(x2-x1)^{2}}$

step 1

Find the distance FG

$F(-2,5),G(6,5)$

substitute the values

$d=\sqrt{(5-5)^{2}+(6+2)^{2}}$

$d=\sqrt{(0)^{2}+(8)^{2}}$

$FG=8\ units$

step 2

Find the distance RF

$R(-2,1),F(-2,5)$

substitute the values

$d=\sqrt{(5-1)^{2}+(-2+2)^{2}}$

$d=\sqrt{(4)^{2}+(0)^{2}}$

$RF=4\ units$

step 3

Find the perimeter

$P=2(L+W)$

we have

$FG=RO=L=8\ units\\RF=OG=W=4\ units$

substitute

$P=2(8+4)=24\ units$

Part 2) Find the area of rectangle FROG

we know that

The area of rectangle is equal to

$A=LW$

we have

$FG=RO=L=8\ units\\RF=OG=W=4\ units$

substitute

$A=(8)(4)=32\ units^2$

8 0

3 years ago

Tom was driving 20.3 meters per second in a 45 mile per hour zone. Was Tom speeding? Explain using a unit conversion as well as

My name is Ann [436]

Answer:

Tom was speeding.

Step-by-step explanation:

The driving speed of Tom = 20.3 meters per second.

Speed allowed in the zone = 45 miles per hour zone.

Since the unit of speed allowed is given in miles per hour but the speed of tom is given in meters per second. So, first, we have to convert the meter per second into mile per hour then we can compare and find that Tom is speeding or not.

1 mile = 1609.34 meters

1 hour = 3600 second

Now convert 20.3 into mile per hour.

20.3 meters per second. = (20.3 / 1609.34)*3600 = 45.40981 mile per hour.

Since Tom’s speed is more than the allowed speed so he is speeding.

7 0

3 years ago

The discriminant of the equation x^2 - 4x + 4 = 0 shows there will be solution(s).

Alex787 [66]

Answer:

one real

Answer: 1

Step-by-step explanation:

Givens

a = 1

b = -4

c = 4

Discriminate

Discriminate = sqrt(b^2 - 4*a*c)

Discriminate = sqrt( (-4)^2 - 4 * (1)(4) )

Discriminate = sqrt ( 16 - 16)

Discriminate = sqrt(0)

Discriminate = 0

That means the 1 real root is - b / 2a = 4/(2*1) = - -2 = 2

3 0

3 years ago