3e^x + 12x = 0
3 ex + 12x = 0 | - 12x
3 ex = -12x | ÷ 3
ex = -4x | ÷ -4
-(ex/4) = x
x = -(ex/4)
You need a graphical or numerical method to find the value of x here.
It's a good idea to draw a graph anyway to get a good initial estimate for an iterative numerical method:
So x ≈ -0.204
.
Thanks for the suggestion.