Respuesta :
Answer:
there are no extraneous solutions to the equation
Step-by-step explanation:
Given
[tex]\sqrt{8x+9}[/tex] = x + 2 ( square both sides )
8x + 9 = (x + 2)² ← expand
8x + 9 = x² + 4x + 4 ( subtract 8x + 9 from both sides )
0 = x² - 4x - 5 ← in standard form
0 = (x - 5)(x + 1) ← in factored form
Equate each factor to zero and solve for x
x - 5 = 0 ⇒ x = 5
x + 1 = 0 ⇒ x = - 1
As a check
Substitute these values into the equation and if both sides are equal then they are the solutions.
x = 5 : [tex]\sqrt{8(5)+9}[/tex] = [tex]\sqrt{49}[/tex] = 7
right side = 5 + 2 = 7
left side = right side ⇒ x = 5 is a solution
x = - 1 : [tex]\sqrt{8(-1)+9}[/tex] = [tex]\sqrt{1}[/tex] = 1
right side = - 1 + 2 = 1
left side = right side ⇒ x = - 1 is a solution
There are no extraneous solutions
Answer:
There are no extraneous solutions
Step-by-step explanation:
sqrt(8x+9) = x+2
Square each side
(sqrt(8x+9))^2 = (x+2)^2
8x+9 = (x+2)^2
FOIL
8x+9 = x^2 +2x+2x+4
Combine like term
8x+9 = x^2 +4x+4
Subtract 8x from each side
8x-8x+9 = x^2 +4x-8x+4
9 = x^2 -4x+4
Subtract 9 from each side
0 = x^2 -4x-5
Factor
0=(x-5) (x+1)
Using the zero product property\
x-5 =0 x+1=0
x=5 x=-1
Check the solutions
x=5
sqrt(8*5+9) = 5+2
sqrt(40+9) = 5+2
sqrt(49) =7
7=7
x=-1
sqrt(8*(-1)+9) = -1+2
sqrt(-8+9) = -1+2
sqrt(1) =1
1=1
Both solutions are true solutions