I don't understand #11 or #12

(12)

10 + 5e^(2x) = 17     subtract 10 from both sides

5e^(2x)  = 7       divide by 5 on each side

e^(2x)  = 7/5  = 1.4      take the ln of both sides

lne^(2x)  = ln1.4      and we can write

(2x) * lne = ln 1.4     and ln e  = 1, so we can ignore this

2x = ln 1.4       divide by 2

x = [ln 1.4 ] / 2  ≈ .168

(11)

4e^x - 4 = 2     divide through by 2

2e^x - 2  = 1    add 2 to both sides

2e^x  =  3        divide both sides by 2

e^x = 3/2  = 1.5    take the ln of both sides

ln e^x = ln 1.5    and we can write

x * ln e = ln 1.5    and ln e  = 1, so we can ignore this

x = ln 1.5 ≈ .4055