Sagot :
Answer:
[tex]81 - {s}^{4} {t}^{4} [/tex]
Step-by-step explanation:
Using FOIL Method
[tex](9 - {s}^{2} {t}^{2} )(9 + {s}^{2} {t}^{2} ) \\ = 81 + 9 {s}^{2} {t}^{2} - 9 {s}^{2} {t}^{2} - {s}^{4} {t}^{4} \\ = 81 - {s}^{4} {t}^{4} [/tex]
Answer:
[tex]81 - {s}^{4} {t}^{4} [/tex]
Step-by-step explanation:
Using FOIL Method
[tex](9 - {s}^{2} {t}^{2} )(9 + {s}^{2} {t}^{2} ) \\ = 81 + 9 {s}^{2} {t}^{2} - 9 {s}^{2} {t}^{2} - {s}^{4} {t}^{4} \\ = 81 - {s}^{4} {t}^{4} [/tex]