Question

Tolong jawab ya nmr 6,7&8 pkai cara,
makasih^_^

Answer 1

6. A.
2x - 5y = -41 ... (1) (× 2)
4x + 3y = 61 ... (2)
__________
4x - 10y = -82
4x + 3y = 61
__________ -
-13y = -143
y = 11

masukkan ke (1),
2x - 55 = -41
2x = 14
x = 7

HP = {7 , 11}



7. D
7x - 4y = 43 ... (1) (×3)
3x + 5y = 5 ... (2) (×7)
_________
21x - 12y = 129
21x + 35y = 35
____________ -
-47y = 94
y = -2

masukkan ke (1),
7x + 8 = 43
7x = 35
x = 5

HP = {5 , -2}



8. A
7x + 3y = 15 ... (1)
y = x - 3 ... (2)

masukkan (2) ke (1),
7x + 3(x - 3) = 15
7x + 3x - 9 = 15
10x = 24
x = 24/10
x = 12/5
x = 2 2/5

masukkan ke (2),
y = 12/5 - 3
y = 12/5 - 15/5
y = -3/5

HP = {2 2/5 , -3/5}