She underestimated by 60 cents. To get this answer all you need to do is multiply 1 dollar times 12 which is $12 and then multiply $.30 by 12 and that gives you $3.60. Then you add the $12 to the $3.60 and that gives you $15.60 which is 60 cents over the estimation.
Assuming 5 is the base. I'm going to leave that out for now.
2log(5x^3) + (1/3)log(x^2+6)
power rule
log(5^2 x^3*2) + log((x^2 + 6)^(1/3))
log(25x^6) + log((x^2 + 6)^(1/3))
quotient rule
log(25x^6 / (x^2 + 6)^(1/3))
20*5= 100
375+100=475
475/5= 95
Therefore the original price of a sweater is $95
