If $7x - 9y = 25$ and $9x - 7y = 23$,then $x + y = \dots$

The pair of equations $y=0$ and $y=-7$ has

Two lines are shown in the following figure.
Which option from the following options is true for the solution of the pair of linear equations in two variables?

Solve the following pair of linear equations by the method of elimination: $2x + 5y = 7$ and $4x + 10y = 12$.

The sum of the present age of a father and twice the present age of a son is $70$ years. Also,the sum of twice the present age of father and the present age of son is $95$ years. Find their present ages.

The sum of a two-digit number and the number obtained by interchanging the digits is always divisible by $\ldots \ldots \ldots \ldots$