Your formatting is ambiguous. Do you mean any of the following?
. . . . .e<sup>4</sup>x + 4 = 5e<sup>2</sup>x
. . . . .e<sup>4x</sup> + 4 = 5e<sup>2</sup>x
. . . . .e<sup>4x + 4</sup> = 5e<sup>2</sup>x
. . . . .e<sup>4</sup>x + 4 = 5e<sup>2x</sup>
. . . . .e<sup>4x</sup> + 4 = 5e<sup>2x</sup>
. . . . .e<sup>4x + 4</sup> = 5e<sup>2x</sup>
Or something else?
Since you posted this to calculus, rather than to algebra, I would guess that you are expected to use some technique from calculus in order to solve this. What have you tried so far?
Thank you.
Eliz.