Re: Finding an unknown value

For this problem you need to solve the equation for v.

Start by substituting the algebraic terms with the values provided, i.e. u = $\displaystyle {4}{5}$ and f = $\displaystyle {2}{3}$.

Therefore, the equation is as follows:

$\displaystyle {1}{4/5} + {1}{v} = {1}{2/3}$

This becomes:

$\displaystyle {5}{4} + {1}{v} = {3}{2}$ - because having '1' on top of a fraction inverts the fraction.

The equation is then solved as follows:

$\displaystyle {5v}{4v} + {4}{4v} = {3}{2}$

$\displaystyle {5v+4}{4v} = {3}{2}$

$\displaystyle 10v+8 = 12v$

$\displaystyle 8 = 2v$

$\displaystyle v = 4$

Re: Finding an unknown value

For this problem you need to solve the equation for v.

Start by substituting the algebraic terms with the values provided, i.e.

$\displaystyle u = 4/5$ and

$\displaystyle f = 2/3$.

Therefore, the equation is as follows:

$\displaystyle {1}/{4}/{5} + 1/v = 1/2/3$

This becomes:

$\displaystyle 5/4 + 1/v = 3/2$ - because having '1' on top of a fraction inverts the fraction.

The equation is then solved as follows:

$\displaystyle 5v/4v + 4/4v = 3/2$

$\displaystyle {5v+4}/{4v} = 3/2$

$\displaystyle 10v+8 = 12v$

$\displaystyle 8 = 2v$

$\displaystyle v = 4$

Re: Finding an unknown value

Quote:

Originally Posted by

**David Green** 1 divided by u, + 1 divided by v, = 1 divided by f

I am required to find the value of V

If u = 4/5

If f = 2/3

Your work is very "messy", David.

Equation is:

1/u + 1/v = 1/f ; isolate v term on left:

1/v = 1/f - 1/u ; substitute values:

1/v = 1/(2/3) - 1/(4/5) ; simplify

1/v = 3/2 - 5/4

1/v = 6/4 - 5/4

1/v = 1/4

v = 4