Posted by Vanessa on Saturday, September 8, 2012 at 5:52pm.
3 x + 2 y = 3 subtract 3 x to both sides
3 x - 3 x + 2 y = 3 - 3 x
2 y = 3 - 3 x Divide both sides by 2
y = 3 / 2 - 3 x / 2
2 x + 10 y = - 5 Subtract 2 x to both sides
2 x - 2 x + 10 y = - 5 - 2 x
10 y = - 5 - 2 x Divide both sides by 10
y = - 5 / 10 - 2 x / 10
y = y
3 / 2 - 3 x / 2 = - 5 / 10 - 2 x / 10 Multiply both sides by 10
10 * 3 / 2 - 10 * 3 x / 2 = 10 * - 5 / 10 - 10 * 2 x / 10
30 / 2 - 30 x / 2 = - 50 / 10 - 20 x / 10
15 - 15 x = - 5 - 2 x Add 2 x to both sides
15 - 15 x + 2 x = - 5 - 2 x + 2 x
15 - 13 x = - 5 Subtract 15 to both sides
15 - 15 - 13 x = - 5 - 15
- 13 x = - 20 Divide both sides by - 13
x = - 20 / - 13
x = 20 / 13
3 x + 2 y = 3
3 * 20 / 13 + 2 y = 3
60 / 13 + 2 y = 3
60 / 13 + 2 y = 3 * 13 / 13
60 / 13 + 2 y = 39 / 13 Subtract 60 / 13 to both sides
60 / 13 - 60 / 13 + 2 y = 39 / 13 + 60 / 13
2 y = - 21 / 13 Divide both sides by 2
y = ( - 21 / 13 ) / 2 = - 21 / ( 13 * 2 ) = - 21 / 26
OR
2 x + 10 y = - 5
2 * 20 / 13 + 10 y = - 5
40 / 13 + 10 y = - 5 * 13 / 13
40 / 13 + 10 y = - 65 / 13 Subtract 40 / 13 to both sides
40 / 13 - 40 / 30 + 10 y = - 65 / 13 - 40 / 13
10 y = - 105 / 13 Divide both sides by 10
y = ( - 105 / 13 ) / 10 = - 105 / ( 13 * 10 ) = - 105 / 130 = - 5 * 21 / ( 5 * 26 ) = - 21 / 26
Solution :
x = 20 / 13 , y = - 21 / 26