# Linear Equations

### Find the value of k so that the pair of equations x + 2y = 5 and 3x + ky + 15 = 0

Find the value(s) of k so that the pair of equations x + 2y = 5 and 3x + ky + 15 = 0 has a unique solution.

### The larger of two supplementary angles exceeds the smaller

The larger of two supplementary angles exceeds the smaller by 18°. Find the angles.

### Sumit is 3 times as old as his son. Five years later

Sumit is 3 times as old as his son. Five years later, he shall be two and a half times as old as his son. How old is Sumit at present ?

### Find the value(s) of k for which the pair of linear equations kx + y = k^2 and x + ky = 1

Find the value(s) of k for which the pair of linear equations kx + y = k2 and x + ky = 1 have infinitely many solutions.

### For what values of m and n the following system of linear equations

For what values of m and n the following system of linear equations has infinitely many solutions.
3x + 4y = 12
(m + n)x + 2(m – n)y = 5m – 1

### In Figure, ABCD is a rectangle. Find the values of x and y

In Figure, ABCD is a rectangle. Find the values of x and y.

### The sum of a two-digit number and the number obtained by reversing the digits is 66

The sum of a two-digit number and the number obtained by reversing the digits is 66. If the digits of the number differ by 2, find the number. How many such numbers are there?

### The ratio of incomes of two persons is 9:7 and the ratio of their expenditures is 4:3

The ratio of incomes of two persons is 9:7 and the ratio of their expenditures is 4:3. If each of them manages to save Rs. 2000 per month, find their monthly incomes.