7log4.²log5+7log49/25

7log4.²log5 + 7log49/25
= 7log2².²log5 + 7log49 - 7log25
= 2(7log2.²log5) + 7log7² - 7log5²
= 2(7log5) + 2(7log7) - 2(7log5)
= 2

⁷log 4 ²log 5 + ⁷log 49 / 25

= 2 ⁷log 2 ²log 5 + 2 ⁷log 7 - ⁷log 5²

= 2 ⁷log 5 + 2 - 2 ⁷log 5

= 2