Use logarithms to solve 9^x=15

According to the rules of logarithms, when you take a log of something to the power of something, you multiply the log of the base by the power, so in this case, taking logs of both sides would give us

xlog9=log15

log9 is a number so we can divide both sides to give us

x=log15/log9=1.23 to 3sf

MB
Answered by Molly B. Maths tutor

7199 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Differentiate y=ln(x)+5x^2, and give the equation of the tangent at the point x=1


The equation 2x^2 + 2kx + (k + 2) = 0, where k is a constant, has two distinct real roots. Show that k satisfies k^2 – 2k – 4 > 0


A particle of mass m moves from rest a time t=0, under the action of a variable force f(t) = A*t*exp(-B*t), where A,B are positive constants. Find the speed of the particle for large t, expressing the answer in terms of m, A, and B.


If y=2x+4x^3+3x^4 and z=(1+x)^2, find dy/dx and dz/dx.


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:

© 2026 by IXL Learning