3log1+3log7+3log49+3log343+3log2401=

10 * 3log7

Pembahasan

3log1 + 3log7 + 3log49 + 3log343 + 3log2401
= 3log(1 x 7 x 49 x 343 x 2401)
= 3log(7^0 x 7^1 x 7^2 x 7^3 x 7^4)
= 3log(7^(0+1+2+3+4))
= 3log(7^10)
= 10 * 3log7