For that last one, this is what I came up with...
5(^3x+2) = 3(^2-x), change to x
ln5 (^3x+2) = ln 3(^2-x)
(3x+12) ln5 = (2-x) ln3 3xln5= (-2) -(2-x) ln3
3x+2 = (2-x)ln3/ ln5 3x ln5 = -x ln3
3x = -x ln3/ln5
Don't know if that is correct.I am also finding these difficult...
ln (y + 5) = 3.1, solve for Y
4 (^x+1) = 6^0.5x, solve for x
I= Imax (1 -e^ -30t/0.01), find T
again, any help would be appreciated