Question

tolong!! dgn detail segera!! yg no 6 gaess

Answer 1

2x - 4y = 7 ...pers.1
5x + y = 1 ...pers.2

5x + y = 1 diubah jadi y = 1 - 5x ....pers.3

Substitusikan pers.3 ke pers.1
2x - 4(1 - 5x) = 7
2x - 4 +20x = 7
22x = 7 + 4
x = 11/22 = 1/2

y = 1 - 5x
y = 1 - 5 × 1/2
y = 1 - 5/2
y = -3/2

Nilai 3x + 5y adalah...
(3 × 1/2) + (5 × -3/2)
= 3/2 + (-15/2)
= 3/2 - 15/2
= -12/2
= -6

Answer 2

X = -1/2
y = 3/2
3x + 5y = 3(-1/2) + 5(3/2)
= -3/2 - 15/2
= -18/2
= -6