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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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