How do you solve this equation using the square root property $(x + 7)^2 = 81$ ?

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Answer 1 · 2015-08-13T15:27:12

The solutions are
$color(blue)(x=2,x=-16$

The square root property involves taking the square root of both the terms on either side of the equation.

Applying the same to the given equation:

$sqrt((x+7)^2)=sqrt(81$

( $sqrt81= color(blue)(+-9$ )

So,
$sqrt((x+7)^2)=color(blue)(+-9$

$(x+7)=color(blue)(+-9$

Solution 1:
$x+7 = +9$
Isolating $x$ completely:
$x+7 -color(blue)(7) = +9 -color(blue)(7)$
$color(blue)(x=2$

Solution 2:
$x+7 = -9$
Isolating $x$ completely:
$x+7-color(blue)(7) = -9-color(blue)(7)$
$color(blue)(x=-16$

How do you solve this equation using the square root property (x + 7)^2 = 81(x + 7)^2 = 81?