Respostas
M = J + C
M = 700 000 + 800 000
M = 1 500 000
12% = 12/100 = 0,12
M = C(1 + i)ⁿ
1 500 000 = 800 000(1 + 0,12)ⁿ
1 500 000 = 800 000 . (1,12)ⁿ
(1,12)ⁿ = 1 500 000 / 800 000
log( (1,12)ⁿ ) = log(1 500 000 / 800 000)
n log(1,12) = log(1 500 000 / 800 000)
n log(1,12) = log(1 500 000) - log(800 000)
n log(1,12) = log(15 . 100 000) - log(8 . 100 000)
n log(1,12) = log(15 . 10⁵) - log(2³ . 10⁵)
n log(1,12) = ( log(15) + log(10⁵) ) - ( log(2³) + log(10⁵) )
n log(1,12) = ( log(15) + 5 . log(10) ) - ( 3 . log(2) + 5 . log(10) )
n log(1,12) = ( 1,18 + 5 . 1 ) - ( 3 . 0,3 + 5 . 1 )
n log(1,12) = ( 1,18 + 5) - ( 0,9 + 5 )
n log(1,12) = 6,18 - 5,9
n log(1,12) = 0,28
log(1,12) = 0,28/n
log(112/100) = 0,28/n
log(112) - log(100) = 0,28/n
log(112) - log(10²) = 0,28/n
log(112) - 2 . log(10) = 0,28/n
2,05 - 2 . 1 = 0,28/n
2,05 - 2 = 0,28/n
0,05 = 0,28/n
n0,05 = 0,28
n = 0,28/0,05
n = 5,6
Resposta: 5,6 anos