plis guys bantu aku no 7 beserta penyelesainanya.

a)
2x - y = 3 ...(1)
2 - 3y = -1
-3y = -1 - 2
-3y = -3
y = 1 ...(2)

substitusi (2) ke (1)
2x - y = 3
2x - 1 = 3
2x = 3 + 1
2x = 4
x = 2

maka x = 2 dan y = 1

b)
x + 2y = 6
x - y = 12
------------------ -
3y = -6
y = -2

x - y = 12
x - (-2) = 12
x + 2 = 12
x = 12 - 2
x = 10

maka nilai x = 10 dan y = -2