**Question 8:**

The variables *x* and *y* are related by the equation $y=\frac{p}{{3}^{x}}$, where k is a constant.

Diagram below shows the straight line graph obtained by plotting ${\mathrm{log}}_{10}y$ against x.

- Express the equation$y=\frac{p}{{3}^{x}}$ in its linear form used to obtain the straight line graph shown in Diagram above.

- Find the value of
*p*.

*Solution:*

**Question 9:**

Variable *x* and *y* are related by the equation ${y}^{2}=p{x}^{q}$ . When the graph *lg y* against *lg x* is drawn, the resulting straight line has a gradient of -2 and an vertical intercept of 0.5 . Calculate the value of *p* and of *q*.*Solution:*

**Question 10:**

Variable *x* and *y* are related by the equation $y=\frac{c}{d-x}$. When the graph y against xy is drawn the resulting line has gradient 0.25 and an intercept on the *y*-axis of 1.25. Calculate the value of c and of *d*.*Solution:*