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2 years ago

Which of the following are solutions to the equation below? check all that apply 4x^2-81=0

Mathematics

2 answers:

Sonbull [250]2 years ago

8 0

Answer:9/2 and -9/2

Step-by-step explanation:

i just did it

seropon [69]2 years ago

3 0

Answer:

9/2

Step-by-step explanation:

$4 {x}^{2} = 81 \\ {x}^{2} = \frac{81}{4} \\ x = \frac{ \sqrt{81} }{ \sqrt{4} } \\ x = \frac{9}{2}$

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Which line has a slope of 0? A: x = 1 B: 3y + 6x = 0 C: y = x D: y = -5

padilas [110]

Answer:

D) y=-5

Step-by-step explanation:

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3 0

2 years ago

Solve for x. 3x+11=9x-14

iVinArrow [24]

Answer:

x=25/6

Step-by-step explanation:

3x+11=9x-14

11=6x-14

25=6x

x=25/6

8 0

2 years ago

Read 2 more answers

Solve the inequality 2x>30+5/4x

insens350 [35]

Answer:

Step-by-step explanation:

$2x > 30+\frac{5}{4x} \\2x-\frac{5}{4x} > 30\\\frac{8x^2-5}{4x} > 30\\case~1\\if~x > 0\\8x^2-5 > 120x\\8x^2-120x > 5\\x^2-15x > \frac{5}{8} \\adding~(-\frac{15}{2} )^2~to~both~sides\\(x-\frac{15}{2} )^2 > \frac{5}{8}+\frac{225}{4} \\(x-\frac{15}{2} )^2 > \frac{455}{8} \\x-\frac{15}{2} < -\sqrt{\frac{455}{8} } \\x < \frac{15}{2}-\sqrt{\frac{455}{8} } \\or~x < 0\\rejected~as~x > 0$

$x-\frac{15}{2} > \sqrt{\frac{455}{8} } \\x > \frac{15}{2} +\sqrt{\frac{455}{8} }$

case~2

$if~x < 0\\8x^2-5 < 120x\\8x^2-120x < 5\\x^2-15x < \frac{5}{8} \\adding~(-\frac{15}{2} )^2\\(x-\frac{15}{2} )^2 < \frac{5}{8} +(-\frac{15}{2} )^2\\|x-\frac{15}{2} | < \frac{5+450}{8} \\-\sqrt{\frac{455}{8} } < x-\frac{15}{2} < \sqrt{\frac{455}{8} } \\\frac{15}{2} -\sqrt{\frac{455}{8} } < x < \frac{15}{2} +\sqrt{\frac{455}{8} } \\but~x < 0\\7.5-\sqrt{\frac{455}{8} } < x < 0$

8 0

1 year ago

a number has seven digits. all the digits are 6 except the hundred-thousands' digit, which is 2, and the thousands' digit, which

klio [65]

Answer:

264,666.

Step-by-step explanation:

We have been given that a number has seven digits.

All digits are 6 except the hundred-thousands' digit.

Hundred thousands: 100,000.

The hundred thousand's digit is 2, so its value would be 200,000.

We have been given that thousands's digit is 4, so its value would be:

4 thousands: 4,000

The number with given hundred thousand's and thousands's digit would be 204,000.

Since all digits are 6 except the hundred-thousands' digit, therefore, our number would be 264,666.

6 0

2 years ago

what is the common number to be subtracted from each term of the ratio 11:8 to get the new ratio 2:1.?

JulijaS [17]

Answer:

5 should be subtracted from each term

Step-by-step explanation:

$\frac{11-x}{8-x}=\frac{2}{1}$

Cross multiply,

1 * (11 - x) = 2*(8-x)

11 -x = 2*8 - 2*x

11 - x = 16 - 2x

Subtract 11 from both sides,

-x = 16 - 2x - 11

-x = 5 - 2x

Add 2x to both sides

-x +2x = 5 - 2 + 2x

x = 5

7 0

2 years ago