Answer
$\left( 3a-7\right) ^{2}$
Work Step by Step
$g\left( a-4\right) ^{2}+30\left( a-4\right) +25=\left( 3\left( a-4\right) \right) ^{2}+2\times \left( 3\left( a-4\right) \right) \times 5+5^{2}=\left( 3\left( a-4\right) +5\right) ^{2}=\left( 3a-7\right) ^{2}$
