Find the solution of 3^{4x} = 9^{(x-1)/2}.

First, recognise that 3^2 = 9. Recall the rule for multiplying indices, that (a^b)^c = a^{bc}. Then, substitute 3^2 in place of 9 to get 3^{4x} = (3^2)^{(x-1)/2}. Use the rule for multiplying indices, so that the equation is now 3^{4x} = 3^{x-1}. This implies 4x=x-1, and therefore 3x = -1, and finally, x = -1/3 is the solution.

CO

Related Further Mathematics GCSE answers

All answers ▸

How would I solve the following equation d^2x/dt^2 + 5dx/dt + 6x = 0


Point A lies on the curve: y=x^2+5*x+8. The x-coordinate of A is -4. What is the equation of the normal to the curve at A?


Given that xy=2 and y=3x+5, find x and y. Do not use trial and improvement.


Work out the equation of the tangent to the curve y=x^2+5x-8 at the point (2,6)