Jawabanmu

2014-06-11T16:01:18+07:00
5x + 2y = -5 |x2|
2x + 3y = 9  |x5|

10x + 4y = -10
10x + 15y = 45       dikurangi

-11y = -55
y = -55 / -11
y = 5

2x + 3y = 9
2x + 3(5) = 9
2x + 15 = 9
2x = 9 - 15
2x = -6
x = -3

x + y = ....
= -3 + 5
= 2

jadikan terbaik ya :)
iy a mksh
sama - sama
ziipp..
2014-06-11T16:02:46+07:00
Agar dapat ditentukan nilai y, maka 5x + 2y = - 5 dikalikan dengan 2, sedangkan 2x + 3y = 9 dikalikan dengan 5, maka:
10x + 4y = -10
10x + 15y = 45 -
-11y = -55
     y = 5

5x + 2y = - 5
5x + 2.5 = -5
5x + 10 = -5
5x = -5-10
5x = -15
x = -3

maka nilai x + y = -3 + 5 = 2