Step-by-step explanation:
Okay so we can start by substituting in
as we know what it is already:
Now at this stage we could use a calculator to figure out what
of
are though a bit of mental math is as easy:
·
·
okay so now we have:
add 10 to both sides to get rid of the
let's get rid of that fraction by multiplying by
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:
now, and we already know what out of is so :
that means
which is ✓
Therefore we know our solution is right.