Question

Solve the following simultaneous equations :
1. x + 2y = 1, 3x - y = 17
3. x + 2y + 9 = 0, 3x + 4y + 17 = 0
5.7x - 2y = 20, 11x + 15y + 23 = 0
74
3y = 8. 18x - 3y = 29​

Answer 1

You should practice more and more equations like this yourself to score high marks in this chapter. I am helping you with one :

1) x+2y = 1

Multiplying above equation with 3 on both sides we get :

3x + 6y = 3 ..........(i)

3x - y = 17 ..........(ii)

Subtracting equation (i) from equation (ii) we get :

3x - y - 3x - 6y = 17 - 3

or, -7y = 14

or, y = -2

Putting the value of y in equation (ii), we get :

3x - (-2) = 17

or, 3x = 17-2

or, x = 15/3