Jika (a+b,a,b) memenuhi sistem persamaan: 3x-y-2z=-1 dan -2x+y+3z=-3 maka a+b=....

3(a+b) - a - 2b = 1
-2(a+b) + a + 3b = -3

3a + 3b - a - 2b = 1 => 2a + b = 1
-2a -2b + a + 3b = -3 => -a + b = -3

3a = 4
a = 3/4

-3/4 + b = -3
b = -2 1/4

a + b = 3/4 - 9/4 = -1,5
jadikan jawaban terbaik ya, thx

(x, y, z) = (a + b, a, b)
3x - y - 2z = -1
3(a + b) - a - 2b = -1
3a + 3b - a - 2b = -1
2a + b = -1

-2x + y + 3z = -3
-2(a + b) + a + 3b = -3
-2a - 2b + a + 3b = -3
-a + b = -3

Eliminasi
2a + b = -1
-a + b = -3
--------------- -
3a = 2 => a = 2/3
-a + b = -3 => b = a - 3 = 2/3 - 3 = -7/3

a + b = 2/3 + (-7/3) = 5/3