$14\times 5\times 765\div\sqrt{2601} = y +658$

Simple Solution:

Given:
$14 \times 5 \times 765 \div \sqrt{2601} = y + 658$

First solve root:
$\sqrt{2601} = 51$

Now:
$14 \times 5 = 70$

$70 \times 765 = 53550$

Divide:
$\frac{53550}{51} = 1050$

So,
$1050 = y + 658$

$y = 1050 - 658 = 392$

Final Answer:

392