nilai x+y memenuhi sistem persamaan 3x + 4y =2 ,3x -4y =20 adalah

3x+4y = 2
3x-4y = 20 (nilai 'y' yg dihilangkan)

3x+3x+4y+(-4) = 2+20
6x +4y-4y = 22
6x = 22
x = 22/6

3x+4y = 2
3 (22/6) + 4y = 2
66/6 + 4y = 2
11 + 4y = 2
4y = 2-11
4y = -9
y = -9/4

x=22/6
y=-9/4

x+y = 22/6+(-9/4)
= 22/6-9/4 = 44/12 - 27/12 = 17/12

Semoga membantu yaa:)