Make x the subject:
Many thanks in advance.
y = (2/3)zx
And this one which I have already done but I need checking:
y = (6x - 7)/3
My answer:
x = (3y + 7)/6
Okay. For the first question, i thought $\displaystyle zx $ was in the numerator.
If $\displaystyle zx $ is in the denominator, then your question becomes $\displaystyle y = \frac{2}{3zx}$ which gives:
$\displaystyle x= \frac{2}{3yz}$
For $\displaystyle y = \frac{1}{2xz}$ you get
$\displaystyle x = \frac{1}{2yz}$
hope that is what you are looking for!