Could some1 plz tell me how to do this equation:
3x+x
8 4=
got no idea how to do it. caould some1 plz reply
I am not sure what you are trying to write here. If you have trouble aligning things, enclose the relevant portions between [code] and [/code] tags.
I would assume you meant $\displaystyle \frac{3x}8 + \frac x4$, but that isn't an equation (this would just be simplifying an expression). Is there something missing to the right of that equal sign?
If it is $\displaystyle \frac{3x}8 + \frac x4,$ just get a common denominator and join the fractions. The least common multiple of 4 and 8 is 8, so we do
$\displaystyle \frac{3x}8 + \frac x4 = \frac{3x}8 + \frac x4{\color{red}\cdot\frac22} = \frac{3x}8 + \frac{2x}{4\cdot2}$
$\displaystyle = \frac{3x}8 + \frac{2x}8 = \frac{3x + 2x}8 = \frac{5x}8$