Question

X² -81 = 0 please help me​

Answer 1

x = 9

Explanation:

• x² -81 = 0 please help me​

x² - 81 = 0

x² = 81

x = √81

x = 9

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• check

9² = 81

81 = 81

the answer is good

Answer 2

`\bold{x_(1)=+9 \: or \: \: x_(2)=-9}`

Step by step explanation:

This question is very simple because it asks us to solve the equation using square roots. We don't need to find any important information as this problem is quite simple. We just need to take into account some rules for moving terms from one member to another and we will get our answer.

Given the equation:

`\bold{{x}^(2) - 81 = 0}`

Move -81−81 to the other member, this subtraction happens by doing the opposite operation, that is, it happens by adding.

`\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:\bold{{x}^(2) = 81}`

We add square root to remove the exponent.

`\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:\bold{{ {x}} = √(81)}`

`\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \bold{x = ±9}`

∴ The solutions we have for this equation are both 9 and -9. And if we want to check our results, we can plug in the values into x and we'll see that both 9 and -9 are values that satisfy the equation, since negatives don't matter when we're squaring numbers.