Is the following statement true or false? The decimal equivalent of 9/4 is a repeating decimal.

Use quadratic formula solve .7x^2 - 28x - 7

beks73 [17]

Answer:

x = 2 + sqrt(5) or x = 2 - sqrt(5)

Step-by-step explanation using the quadratic formula:

Solve for x over the real numbers:

7 (x^2 - 4 x - 1) = 0

Divide both sides by 7:

x^2 - 4 x - 1 = 0

Add 1 to both sides:

x^2 - 4 x = 1

Add 4 to both sides:

x^2 - 4 x + 4 = 5

Write the left hand side as a square:

(x - 2)^2 = 5

Take the square root of both sides:

x - 2 = sqrt(5) or x - 2 = -sqrt(5)

Add 2 to both sides:

x = 2 + sqrt(5) or x - 2 = -sqrt(5)

Add 2 to both sides:

Answer: x = 2 + sqrt(5) or x = 2 - sqrt(5)

6 0

3 years ago

What is the mean for the following set of data? 2,5, 7, 8, 11, 11, 12 10 11 8

Yuri [45]

Add up all the numbers & divide by the number of numbers. That should give you the mean.

4 0

3 years ago

Read 2 more answers

Please help me with these questions , thank you

Angelina_Jolie [31]

Answer:

1. 4 $x^{3}$ + 26x² + 4x - 48

2. 2 $x^{3}$ - 23x² + 60x - 32

3. $x^{5}$ + 7 $x^{3}$ - 4x + 2 $x^{4}$ + 14x² - 8

4. 2 $x^{7}$ + $x^{6}$ - 28 $x^{5}$ + 3x + 12

Step-by-step explanation:

To multiply polynomials, simply distribute whatever's outside the largest set of parenthesis, then combine like terms.

1) Distribute the parenthesis (x + 6):

x(4x² + 2x - 8) + 6(4x² + 2x - 8)

4 $x^{3}$ + 2x² -8x + 6(4x² + 2x -8)

4 $x^{3}$ + 2x² -8x + 24x² + 12x - 48

Combine like terms:

4 $x^{3}$ + 26x² + 4x - 48

2) Distribute the parenthesis (x - 8):

x(2x² - 7x + 4) + (-8)(2x² - 7x + 4)

2 $x^{3}$ - 7x² + 4x + (-8)(2x² - 7x + 4)

2 $x^{3}$ - 7x² + 4x + -16x² + 56x - 32

Combine like terms:

2 $x^{3}$ - 23x² + 60x - 32

3) Distribute the parenthesis (x + 2):

x( $x^{4}$ + 7x² - 4) + 2( $x^{4}$ + 7x² - 4)

$x^{5}$ + 7 $x^{3}$ - 4x + 2( $x^{4}$ + 7x² - 4)

$x^{5}$ + 7 $x^{3}$ - 4x + 2 $x^{4}$ + 14x² - 8

No like terms to combine, so:

$x^{5}$ + 7 $x^{3}$ - 4x + 2 $x^{4}$ + 14x² - 8

4) Distribute the parenthesis (x + 4):

x(2 $x^{6}$ - 7 $x^{5}$ + 3) + 4(2 $x^{6}$ - 7 $x^{5}$ + 3)

2 $x^{7}$ - 7 $x^{6}$ + 3x + 4(2 $x^{6}$ - 7 $x^{5}$ + 3)

2 $x^{7}$ - 7 $x^{6}$ + 3x + 8 $x^{6}$ - 28 $x^{5}$ + 12

Combine like terms:

2 $x^{7}$ + $x^{6}$ - 28 $x^{5}$ + 3x + 12

hope this helps!

8 0

2 years ago

Help plz

sergiy2304 [10]

3(5y-6)-2y=8
15y-18-2y=8
13y-18=8
13y=26
y=2
That is because you have the expression you can substitute it on the system.( hope this helps)

7 0

3 years ago

Read 2 more answers

20 points!! Solve this system of lineal equations.separate the x- and y- values with a comma

Zielflug [23.3K]

Solve the following system:{12 x = 54 - 6 y | (equation 1)-17 x = -6 y - 62 | (equation 2)
Express the system in standard form:{12 x + 6 y = 54 | (equation 1)-(17 x) + 6 y = -62 | (equation 2)
Swap equation 1 with equation 2:{-(17 x) + 6 y = -62 | (equation 1)12 x + 6 y = 54 | (equation 2)
Add 12/17 × (equation 1) to equation 2:{-(17 x) + 6 y = -62 | (equation 1)0 x+(174 y)/17 = 174/17 | (equation 2)
Multiply equation 2 by 17/174:{-(17 x) + 6 y = -62 | (equation 1)0 x+y = 1 | (equation 2)
Subtract 6 × (equation 2) from equation 1:{-(17 x)+0 y = -68 | (equation 1)0 x+y = 1 | (equation 2)
Divide equation 1 by -17:{x+0 y = 4 | (equation 1)0 x+y = 1 | (equation 2)
Collect results:Answer: {x = 4 {y = 1

Please note the { are supposed to span over both equations but it interfaces doesn't allow it. Please see attachment for clarification.

7 0

3 years ago