Question

resolva a equação irracional:
x+raizdex+7=5

Answer 1

$x+ \sqrt{x+7}= 5 \\ \\ \sqrt{x+7}= 5-x \\ \\ x+7= (5-x)^2 \\ \\ x+7=(5)^2+2*5*(-x)+(-x)^2 \\ \\ x+7= 25-10x+x^2 \\ \\ 0= 25-10x+x^2-x-7 \\ \\ 0= x^2-10x-x-7+25 \\ \\ 0= x^2-11x+18 \\ \\ 0= (x-2)(x-9) \\ \\ 0=x- 2\qquad \qquad 0=x-9 \\ \\ \boxed{x_1=2}\qquad \qquad \quad \boxed{x_2=9}$