10x-3y=69 2x-9y=39 find x and y

10x - 3y = 69   ...(1)

2x - 9y = 39    ...(2)

Multiply (1) throughout by 3

30x - 9y = 207   ...(3)  Rewrite (2) below it

2x - 9y = 39      ...(2)

Subtract (2) from (3)

28x - 0 = 207-39 or

28x = 168

Divide both sides by 28

x = 168/28 or

x = 6

Put this back into equation (2)  (or equation (1), whichever you prefer);

2*6 - 9y = 39 or

12 - 9y = 39

Subtract 12 from both sides

-9y = 27

multiply both sides by -1

9y = -27

Divide both sides by 9

y = -27/9

y = -3

so x = 6 and y = -3