Solve the following pair of equations: $(a \neq 0, b \neq 0)$
$\frac{2}{a} + \frac{3}{b} = 1$
$\frac{1}{a} + \frac{1}{b} = 1$

The solution set of a pair of equations $5x - 5y = -5$ and $\frac{3x}{2} - \frac{3y}{2} + \frac{3}{2} = 0$ is.........

For the linear equation of two variables $ax + by + c = 0$,$\ldots \ldots \ldots \ldots$ is not true.

If a pair of equations $3x + ky - 9 = 0$ and $x + 2y - 3 = 0$ has infinite solutions,then $k = \ldots$

Places $A$ and $B$ are $90\, km$ apart from each other on a highway. $A$ car starts from $A$ and another from $B$ at the same time. If they move in the same direction,they meet in $9$ hours and if they move in opposite directions,they meet in $\frac{9}{7}$ hours. Find the speeds of the cars.

The angles of a cyclic quadrilateral $ABCD$ are $\angle A = (6x + 10)^{\circ}$,$\angle B = (5x)^{\circ}$,$\angle C = (x + y)^{\circ}$,and $\angle D = (3y - 10)^{\circ}$. Find $x$ and $y$,and hence the values of the four angles.