Question

Selesaikan sistem persamaan berikut dengan metode substitusi,untuk x,y { R

2x+2y = 5 dan 4x-3y = -18

Answer 1

2x+2y = 5 (disederhanakan (dibagi 2))
x+y = 5/2
x = 5/2-y

=> 4x-3y = -18
=> 4(5/2-y)-3y = -18
=> 10-4y-3y = -18
=> -7y = -18-10
=> -7y = -28
=> y = -28/-7
=> y = 4

nilai x :
=> 4x-3y = -18
=> 4x-12 = -18
=> 4x = -18+12
=> 4x = -6
=> x = -6/4 = -3/2

=> (x,y) = (-3/2, 4)

Answer 2

2x+2y=5(dibuat persamaan baru) menjadi2x=5-2y sehingga x=2,5-y
4x-3y=-18
4(2,5-y)-3y=-18 (nilai x disubstitusikqn)
10-4y-3y=-18
10-7y=-18
28=7y
y=4

4x-3y=-18
4×-3(4)=-18
4x-12=-18
4x=-6
x=-3/2