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Sqrt(x+4)=2-x
help me pleaseeeeeee

User JohanVdR
by
2.8k points

2 Answers

13 votes
13 votes

Answer:

x = 0

Explanation:


√(x+4) = 2 - x ( square both sides to clear the radical )

x + 4 = (2 - x)² ← expand using FOIL

x + 4 = 4 - 4x + x² ( subtract x + 4 from both sides )

0 = x² - 5x ← factor out x from each term

0 = x(x - 5)

equate each factor to zero and solve for x

x = 0

x - 5 = 0 ⇒ x = 5

As a check

substitute these values into the equation and if both sides are equal then they are the solutions

x = 0

left side =
√(0+4) =
√(4) = 2

right side = 2 - 0 = 2

then x = 0 is a solution

x = 5

left side =
√(5+4) =
√(9) = 3

right side = 2 - 5 = - 3 ≠ 3

then x = 5 is an extraneous solution

User Kachina
by
2.7k points
22 votes
22 votes

Answer:
x=\Large\boxed{0}

Explanation:

Given expression


√(x+4) =2-x

Square both sides of the equation


√(x+4)^2 =(2-x)^2


x+4=4-4x+x^2

Subtract x on both sides


x+4-x=4-4x+x^2-x


4=x^2-5x+4

Subtract 4 on both sides


4-4=x^2-5x+4-4


0=x^2-5x

Factorize the quadratic expression


0=x(x-5)


x=\Large\boxed{0} \text{ or }x=5~(reject)\text{ }

Check the answer


\text{When x = 0:}


√((0)+4) =2-(0)


√(4)=2


2=2
\boxed{TRUE}


\text{When x = 5:}


√((5)+4) =2-(5)


√(9)=-3


3\\eq -3
\boxed{FALSE}

Hope this helps!! :)

Please let me know if you have any questions

User AvaTaylor
by
3.0k points