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How do you solve #3x² = 21#?

Answer 1

Isaiah Anthony

#color(green)( x = +sqrt7 #
#color(green)( x = -sqrt7#

#3x² = 21#

#3x² - 21=0# Here #3# is common to both terms:

#3(x² - 7)=0#

#x² - 7=0#

#x² = 7# # x = +-sqrt7#

The solutions are: #color(green)( x = +sqrt7 , x = -sqrt7#

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Answer 2

Eva Abramson

To solve the equation 3x² = 21, follow these steps:

Divide both sides of the equation by 3 to isolate x²: x² = 7.
Take the square root of both sides of the equation: x = ±√7.
The solutions are x = √7 and x = -√7.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.