The given equation is,

It can be rewritten in the form of y=mx+c, where c is the y intercept.
Hence,

Put different values for x and find value of y.
When x=0, y=1.
When x=1,

The graph is,
I think what you meant was
(2x - 5)² = 11 -- (1)
Square root both sides of (1), i.e.
√(2x - 5)² = ± √11 -- (2)
From (2), we have
2x - 5 = ± √11 -- (3)
By adding 5 to both sides in (3), we have
2x = 5 ± √11 -- (4)
Divide both sides of (4) by 2, and we obtain
x = (5 ± √11)/2 -- (5)
From (5), the solution set of (1) is
x = (5 + √11)/2, (5 - √11)/2 ...Ans.
5 rows x 4 in each = 20 chairs in the classroom
The answer would be six and 1 tenths or 6 and 1/10