Question

Penyelesaian dari sistem persamaan linear 2x + 5y = 1 dan x - 2y = 5 adalah p dan q.nilai dari p + q adalah
a.-4
b.-2
c.2
d.4

Answer 1

Verified answer

2x + 5y = 1
x - 2y = 5

x - 2y = 5
x = 5 + 2y
x = 2y + 5

2x + 5y = 1
2(2y + 5) + 5y = 1
4y + 10 + 5y = 1
9y = 1 - 10
9y = - 9
y = - 1

x = 2y + 5
x = - 2 + 5
x = 3

p + q
= x + y
= 3 - 1
= 2

Jawaban : c. 2

Maaf Kalau Salah

Answer 2

Persamaan (1) : 2x + 5y = 1 |x1 |2x + 5y = 1
Persamaan (2) : x - 2y = 5 |x2|2x - 4y = 10
_________ -
9y = -9
y = -9/9
y = -1

Persamaan (1) : 2x + 5y = 1 |x2|4x + 10y = 2
Persamaan (2) : x - 2y = 5 |x5|5x - 10y = 25
__________ +
9x = 27
x = 27/9
x = 3

Nilai p + q :
p = 3
q = -1

3 + -1
= 2 (c)