Solve the square root equation

Question

also how do you check for extraneous solutions? Thanks. 

 

Square root of 1-x=x+3

Answer 1

start off by squaring both sides of the equation 

 

(1 - x )  = ( x+3)^2

 

( 1 - x) = x^2 + 6x + 9 

 

x^2 + 7x + 8 = 0 

 

You are going to have to use the quadratic formula to find the roots of the above equation

 

x =[ -7 +/- sqrt ( 49 - 32) ] / 2

 

x = (-7 + sqrt (17) ) / 2 and x = ( -7 - sqrt (17) ) / 2

 

Use a calculator to find the 2  above values of x.