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**Punch** Variables x and y are related by the equation $\displaystyle y = \frac{ax}{x-b}$. The graph of y against $\displaystyle \frac{y}{x}$ has gradient 3 and y-intercept 2.

(a) Find the value of a and of b.

(b) Find the values of x for which x = y.

**Attempted Solution**

(a) $\displaystyle y = \frac{ax}{x-b}$

$\displaystyle yx-yb = ax$

$\displaystyle \frac{yx}{x} - \frac{yb}{x} = \frac{ax}{x}$

$\displaystyle y - \frac{yb}{x} = a$

$\displaystyle y = b\frac{y}{x} + a$

b=3 , a=2

Unclear of doing part B