Question

Diketahui sistem persamaan linear
x + y = 3
2x - z = 3
y - 2z = 4
nilai x (y + z) adalah....

Answer 1

X + y = 3 x2
2x - z = 3 x1

2x + 2y = 6
2x - z = 3
____________ -
2y + z = 3

y - 2z = 4 x1
2y + z = 3 x2

y - 2z = 4
4y + 2z = 6
___________ +
5y = 10
y = 2

y-2z = 4
2 - 2z = 4
-2z = 2
z = -1

x + y = 3
x + 2 =3
x = 1

y + z = 2--1 = 2 + 1 = 3