Question 205199
√a-1-5=1 
Assume the problem is:
{{{sqrt(a-1) - 5}}} = 1
Add 5 to both sides
{{{sqrt(a-1)}}} = 1 + 5
{{{sqrt(a-1)}}} = 6
Square both sides
a - 1 = 36
:
a = 36 + 1
a = 37
;
:
Check solution in original equation
{{{sqrt(37-1)- 5}}} = 1
{{{sqrt(36)- 5}}} = 1
 6 - 5 = 1