tentukan subsitusi 1.) 6x+7y=9 dan 8x-y=43 2.) 3x+8y=18 dan x-3y=-11 dijawab secepatnya ya, plisss

1]
8x - y = 43
y = 8x - 43

6x + 7y = 9
6x + 7(8x - 43) = 9
6x + 56x - 301 = 9
62x - 301 = 9
62x = 9 + 301
62x = 310
x = 310/62
x = 5

8x - y = 43
8(5) - y = 43
40 - y = 43
y = 40 - 43
y = -3

Jadi nilai x dan y adalah (5,-3)

2]
x - 3y = -11
x = 3y - 11

3x + 8y = 18
3(3y - 11) + 8y = 18
9y - 33 + 8y = 18
17y - 33 = 18
17y = 18 + 33
17y = 51
y = 51/17
y = 3

x - 3y = -11
x - 3(3) = -11
x - 9 = -11
x = -11 + 9
x = -2

Jadi nilai x dan y adalah (-2,3)