$2 \color{#FF6800}{ a } a ^ { 2 } b ^ { 3 } \times 3 b$
$ $ If the exponent is omitted, the exponent of that term is equal to 1 $ $
$2 \color{#FF6800}{ a } ^ { \color{#FF6800}{ 1 } } a ^ { 2 } b ^ { 3 } \times 3 b$
$2 \color{#FF6800}{ a } ^ { \color{#FF6800}{ 1 } } \color{#FF6800}{ a } ^ { \color{#FF6800}{ 2 } } b ^ { 3 } \times 3 b$
$ $ Add the exponent as the base is the same $ $
$2 \color{#FF6800}{ a } ^ { \color{#FF6800}{ 1 } \color{#FF6800}{ + } \color{#FF6800}{ 2 } } b ^ { 3 } \times 3 b$
$2 a ^ { \color{#FF6800}{ 1 } \color{#FF6800}{ + } \color{#FF6800}{ 2 } } b ^ { 3 } \times 3 b$
$ $ Add $ 1 $ and $ 2$
$2 a ^ { \color{#FF6800}{ 3 } } b ^ { 3 } \times 3 b$
$2 a ^ { 3 } b ^ { 3 } \color{#FF6800}{ b } \times 3$
$ $ If the exponent is omitted, the exponent of that term is equal to 1 $ $
$2 a ^ { 3 } b ^ { 3 } \color{#FF6800}{ b } ^ { \color{#FF6800}{ 1 } } \times 3$
$2 a ^ { 3 } \color{#FF6800}{ b } ^ { \color{#FF6800}{ 3 } } \color{#FF6800}{ b } ^ { \color{#FF6800}{ 1 } } \times 3$
$ $ Add the exponent as the base is the same $ $
$2 a ^ { 3 } \color{#FF6800}{ b } ^ { \color{#FF6800}{ 3 } \color{#FF6800}{ + } \color{#FF6800}{ 1 } } \times 3$
$2 a ^ { 3 } b ^ { \color{#FF6800}{ 3 } \color{#FF6800}{ + } \color{#FF6800}{ 1 } } \times 3$
$ $ Add $ 3 $ and $ 1$
$2 a ^ { 3 } b ^ { \color{#FF6800}{ 4 } } \times 3$