diketahui 2x+y=4 2x-2y=-1 tentukan nilai 2x-7y

Materi : SPLDV

Pembahasan :
2x + y = 4
2x - 2y = -1
——————— (-)
3y = 5
y = 5/3

Substitusi..
x - y = -1/2
x - 5/3 = -1/2
x = -1/2 + 5/3
x = -3/6 + 10/6
x = 7/6

Maka...
2x - 7y
= 2(7/6) - 7(5/3)
= 7/3 - 35/3
= - 28/3