[tex]\quad \huge \quad \quad \boxed{ \tt \:Answer }[/tex]
[tex]\qquad \tt \rightarrow \: (3 {a}^{2} - 7xy)(3 {a}^{2} + 7xy) = 9 {a}^{ 4 } - 49 {x}^{2} {y}^{2} [/tex]
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[tex] \large \tt Solution \: : [/tex]
[tex]\qquad \tt \rightarrow \: (3 {a}^{2} - 7xy)(3 {a}^{2} + 7xy)[/tex]
[tex]\qquad \tt \rightarrow \:(3 {a}^{2} \sdot3 {a}^{2} ) + (3a {}^{2} \sdot7xy) - (7xy \sdot3 {a}^{2} ) - (7xy \sdot7xy)[/tex]
[tex]\qquad \tt \rightarrow \:9 {a}^{4} + 21a {}^{2} xy- 21 {a}^{2} xy - 49 {x}^{2} {y}^{2} [/tex]
[tex]\qquad \tt \rightarrow \: 9 {a}^{ 4 } - 49 {x}^{2} {y}^{2} [/tex]
or
Apply property :
[tex]\qquad \tt \rightarrow \: (p + q)(p - q) = {p}^{2} - {q}^{2} [/tex]
Answered by : ❝ AǫᴜᴀWɪᴢ ❞
