All categories

2 years ago

Which expression is equivlent to (3^2)^-2?A) -81B) -12C) 1/81D) 1/12

Mathematics

2 answers:

Colt1911 [192]2 years ago

6 0

Answer:

Answer: 1/81

First you simplify it to 3^-4

Then express it with a positive exponent

which goes to 1/3^4

Then evaluate it to 1/81

Andreyy892 years ago

4 0

Answer:

C) 1/81

Step-by-step explanation:

According to PEMDAS, you need to work on Parentheses first, so you should square 3.

3×3 = 9

A rule of exponents is that you can't have negative exponents, and if they show up you need to flip the side the exponent is at. (If it were at the denominator it would then have to be at the numerator)

Since the negative exponent was at (what is understood as) the numerator, you have to place it at the denominator.

Your equation should now be

1/ 9^2

Square 9

And the answer should be

1/81

You might be interested in

How can I make 25/3 into a mixed number

Usimov [2.4K]

Answer:

Step-by-step explanation:

25/3 3 goes into 25 8 times with 1 left over. 8 1/3 is your answer

6 0

2 years ago

If y varies directly as the square root of x and y = 8 when x = 36, find the value of y when x = 144. y =

Wittaler [7]

Answer:

y=32

Step-by-step explanation:

cross multiply

36/4 *144/y

144*8/36

=1152/36

y=32

8 0

2 years ago

Can someone help me? I give you brainlest who ever types it first

Tatiana [17]

Answer:

Put the question that you need help on.

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

Please help me with my homework

Anna35 [415]

Answer:

x=90 y=58 z=32

Step-by-step explanation:

I don't know how to explain it but yea

8 0

2 years ago

What is the solution of

kobusy [5.1K]

Answer:

Third option: x=0 and x=16

Step-by-step explanation:

$\sqrt{2x+4}-\sqrt{x}=2$

Isolating √(2x+4): Addind √x both sides of the equation:

$\sqrt{2x+4}-\sqrt{x}+\sqrt{x}=2+\sqrt{x}\\ \sqrt{2x+4}=2+\sqrt{x}$

Squaring both sides of the equation:

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

Simplifying on the left side, and applying on the right side the formula:

$(a+b)^{2}=a^{2}+2ab+b^{2}; a=2, b=\sqrt{x}$

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

Isolating the term with √x on the right side of the equation: Subtracting 4 and x from both sides of the equation:

$2x+4-4-x=4+4\sqrt{x}+x-4-x\\ x=4\sqrt{x}$

Squaring both sides of the equation:

$(x)^{2}=(4\sqrt{x})^{2}\\ x^{2}=(4)^{2}(\sqrt{x})^{2}\\ x^{2}=16 x$

This is a quadratic equation. Equaling to zero: Subtract 16x from both sides of the equation:

$x^{2}-16x=16x-16x\\ x^{2}-16x=0$

Factoring: Common factor x:

x (x-16)=0

Two solutions:

1) x=0

2) x-16=0

Solving for x: Adding 16 both sides of the equation:

x-16+16=0+16

x=16

Let's prove the solutions in the orignal equation:

1) x=0:

$\sqrt{2x+4}-\sqrt{x}=2\\ \sqrt{2(0)+4}-\sqrt{0}=2\\ \sqrt{0+4}-0=2\\ \sqrt{4}=2\\ 2=2$

x=0 is a solution

2) x=16

$\sqrt{2x+4}-\sqrt{x}=2\\ \sqrt{2(16)+4}-\sqrt{16}=2\\ \sqrt{32+4}-4=2\\ \sqrt{36}-4=2\\ 6-4=2\\ 2=2$

x=16 is a solution

Then the solutions are x=0 and x=16

5 0

2 years ago

Which expression is equivlent to (3^2)^-2?A) -81B) -12C) 1/81D) 1/12​

Which expression is equivlent to (3^2)^-2?A) -81B) -12C) 1/81D) 1/12