Question

Selesaian dari sistem persamaan 3x + y = -1 dan x + 3y = 5 adalah..
A.(1,-2)
B.(-1,2)
C.(2,-1)
D.(-2,1)
Tlg bantu pake cara yaa

Answer 1

Verified answer

3x + y = -1 |×1
x + 3y = 5 |×3

3x +y = -1
3x +9y = 15
_________-
-8y = -16
y = -16/-8
y = 2

x + 3y = 5
x +3(2) = 5
x = 5-6
x = -1

hp = {-1,2} ➡ B

semoga membantu

Answer 2

3x + y = -1 | ×1 | 3x + y = -1
x + 3y = 5 | ×3 | 3x + 9y = 15
(3x nya di coret, sisa nya dikurang)
-8y = -16
y = -16/-8
y = 2

3x + y = -1
3x + 2 = -1
3x = -1 - 2
3x = -3
x = -3/3
x = -1

C. (2,-1)