Solve the following problem: (u + 3)/8 = 5/ (u -3)

(u+ 3)/8 = 5/(u-3).

To solve
the equation, we need to cross multiply.

==>
(u+3)*(u-3) = 8*5

==> (u+3)(u-3) =
40.

Now we will expand the
brackets.

==> u*u + 3*u + u*-3 + 3*-3 =
40

==> u^2 + 3u - 3u - 9 =
40

Now we will reduce similar
terms.

==> u^2 - 9 =
40

Now we will add 9 to both
sides.

==> u^2 =
40+9

==> u^2 = 49.

Now
we will take the root of both sides.

==> u= +-
7.

Then, there are two possible values for u that satisfies
the equation.

==> u = { -7,
7}