Have a look at https://socratic.org/help/symbols for formatting. Note the hash at the beginning and end of the typed text. This triggers the implementation of mathematical formatting.

Given: #x/4=3/11#

Our target is to have #x# on its own on one side of the equals and all the numbers on the other side

#color(red)("First principles method")#

If we can change the #1/4#bit from #x/4# into 1 then #x xx1->x# and we have solved it.

Write as

#color(green)(x xx1/4=3/11)#

Multiply both sides by #color(red)(4)#

#color(green)(x xx1/4color(red)(xx4)color(white)("ddd")=color(white)("ddd")3/11color(red)(xx4))#

#color(green)(color(white)("dd")x xx(color(red)(4))/4color(white)("dddd")=color(white)("ddd")(3color(red)(xx4))/11)#

#color(white)("dd")x xx1color(white)("ddddd") =color(white)("ddd")12/11#

#x=12/11#

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#color(red)("Shortcut method ")#

#color(brown)("Basically this is just remembering what happens with first principles")#

Consider the 4 from #x/4#

This is #x-:4# so move the 4 to the other side of the equals and use the opposite action to divide. Which is multiply.

So #x/4=3/11 color(white)("d")->color(white)("d")color(white)("d")x=3/11xx4#

#x=12/11#