[tex]x=200[/tex]
Explanation:
Okay so we can start by substituting in [tex]y[/tex] as we know what it is already:
[tex](\frac{1}{5} )x-(\frac{2}{3} )(15)=30[/tex]
Now at this stage we could use a calculator to figure out what [tex]\frac{2}{3}[/tex] of [tex]15[/tex] are though a bit of mental math is as easy:
[tex](\frac{15}{3} )[/tex] · [tex]2=[/tex] [tex]5[/tex] · [tex]2[/tex]
okay so now we have:
[tex](\frac{1}{5} )x-10=30[/tex] add 10 to both sides to get rid of the [tex]-10[/tex]
[tex](\frac{1}{5})x=40[/tex] let's get rid of that fraction by multiplying by [tex]5[/tex]
and there's the solution for x
We can check we got this right by substituting it back into the original equation with the known y:
[tex](\frac{1}{5} )(200)-(\frac{2}{3})(15)=30[/tex]
now, and we already know what out of is so :
that means
which is ✓
Therefore we know our solution is right.
