$\"\"$

The expression is 9 + 18 + 36 + . . . . . . . +1152.

The 1st term of the sequence is 9 and

common ratio is $\"\"$

(Apply nth term of the geometric sequence formula: $\"\"$ )

$\"\"$ (Substitute 9 for $\"\"$ , 2 for r, 1152 for $\"\"$ )

$\"\"$ (Divide each side by 9)

$\"\"$ (Simplify) $\"\"$

$\"\"$ (Apply formula: $\"\"$ )

$\"\"$ (Multiply each side by 2)

$\"\"$ (Simplify)

n = 8 (Apply formula: $\"\"$ )

9 + 18 + 36 + . . . . . . . +1152 = $\"\"$ $\"\"$

The summation notation of the sum is $\"\"$ .