Answer:
x= 5 ........................ .......
Solution is supposed to be as follows
<span>u+<span>2 / 3</span><span> u<span>^3/2</span></span>
=r+<span>2 / 3</span><span> r^<span>3/2</span></span> + <span>c</span></span>
There are two methods I know. hope it'd help :)