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liraira [26]
3 years ago
8

Why is -9an acceptable answer to the equation x2=81 ?

Mathematics
2 answers:
Arte-miy333 [17]3 years ago
8 0

Answer:

X=9 or x=-9

Step-by-step explanation:

X^2=81

Can be written as

x^2-81=0

Factorize by the property:

a^2-b^2=(a-b)(a+b)

So the expression becomes:

(x-9)(x+9)=0

Therefore, either x-9=0or x+9=0

Then the solutions are x=9 or x=-9

Zielflug [23.3K]3 years ago
4 0

Step-by-step explanation:

Because square of a negative number gives a positive number, that's why - 9 is an acceptable answer to the equation x^2 = 81

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Evgesh-ka [11]
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2 years ago
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vazorg [7]

Answer:

-2/4,  8/40, 21/30, 9, 9 20/25

Step-by-step explanation:

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2 years ago
A motorboat travels 275 kilometers in 5 hours going upstream. It travels 405 kilometers going downstream in the same amount of t
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Step-by-step explanation:

275 \times 5 = 1375

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405 \times 5 = 2025

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4 0
3 years ago
Find the product 4.51 x 3.4
kifflom [539]
 Multiply 4.51 by 3.4 
That's all it is asking you
8 0
3 years ago
Read 2 more answers
The mass of the sun is 21.3525×102921.3525×1029 kg. the mass of mercy is 328.5×1021328.5×1021 kg.how many times larger is the ma
Liono4ka [1.6K]
This is basically a simple problem to understand. The only thing that needs to be done is to divide the mass of the sun by the mass of mercury. It will give the required result.

Number of times the mass of sun is greater than
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I hope that this is the answer that you were looking for and it has come to your great help.</span>
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3 years ago
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