Answer:
Answer is 2×c + log [10^{a} + 10^{b}] +a
Explanation:
log 2 = a ,log 3 = b , log 7 = c
Using formula
log d×e = log d + log e
log d^{a} = a×log d
log 5 = log [10^{a} + 10^{b}]
log 490 in terms of a , b and c and you can have integer coefficients
log 490
= log 7^{2}×5×2
= 2×log 7 + log 5 + log 2
= 2×c + log [10^{a} + 10^{b}] +a
Answer is 2×c + log [10^{a} + 10^{b}] +a