${3}^{2}{y}^{4}-49$
Factor the number $4$${3}^{2}{y}^{2 \times 2}-49$
Write the number in the exponential form with an exponent of $2$${3}^{2}{y}^{2 \times 2}-{7}^{2}$
Use ${a}^{mn}={\left( {a}^{n} \right)}^{m}$ to transform the expression${3}^{2} \times {\left( {y}^{2} \right)}^{2}-{7}^{2}$
Multiply the terms with equal exponents by multiplying their bases${\left( 3{y}^{2} \right)}^{2}-{7}^{2}$
Use ${a}^{2}-{b}^{2}=\left( a-b \right)\left( a+b \right)$ to factor the expression$\left( 3{y}^{2}-7 \right) \times \left( 3{y}^{2}+7 \right)$