Find the exact solutions, in their simplest form, to the equations : a) 2ln(2x + 1)-4=0 b)7^(x)e^(4x)=e^5

a) 2ln(2x + 1)-4=0

-> ln(2x + 1)-2=0

-> ln(2x + 1)=2

-> (2x + 1)=e2

-> 2x = e-1

-> x = (e-1)/2

b) 7xe4x=e5

-> 7x=e\ e4x

​​​​​​​-> 7x=e5-4x

​​​​​​​-> ln(7x)=5-4x

​​​​​​​-> xln(7)=5-4x

​​​​​​​-> x(ln(7)+4)=5

​​​​​​​-> x=5/(ln(7)+4)

EL
Answered by Elizabeth L. Maths tutor

4653 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Line AB, with equation: 3x + 2y - 1 = 0, intersects line CD, with equation 4x - 6y -10 = 0. Find the point, P, where the two lines intersect.


The point A lies on the curve with equation y = x^(1/2). The tangent to this curve at A is parallel to the line 3y-2x=1. Find an equation of this tangent at A. (PP JUNE 2015 AQA)  


What are the main factors when deciding whether or not the Poisson distribution is a suitable model?


How do I differentiate a pair of parametric equations?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning