three

four

(2)

a= 12

b=5

This is the fourth equation.

(3)

Equation:

(2n+4)/x- 1/(x-n- 1)= 1

Its root is x 1=n+2.

x2=2n+2

Verification: x 1 has been replaced.

(2n+4)/(n+2)- 1/ 1 = 2- 1 = 1

X2 substitution

(2n+4)/(2n+2)- 1/(n+ 1)=(n+ 1)/(n+ 1)= 1