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 = e2 -1

-> x = (e2 -1)/2

b) 7xe4x=e5

-> 7x=e5 \ e4x

​​​​​​​-> 7x=e5-4x

​​​​​​​-> ln(7x)=5-4x

​​​​​​​-> xln(7)=5-4x

​​​​​​​-> x(ln(7)+4)=5

​​​​​​​-> x=5/(ln(7)+4)

EL

Related Maths A Level answers

All answers ▸

Differentiate x^3 + 6x + 1


Solve, correct to 2 decimal places, the equation cot(2x)=3 for 0°<x<180°


Find the equation of the tangent to the curve y = 2x^2 + x - 1 at the point where x = 1.


Express x^2 + 5x + 10 in the form (x+p)^2 +q