Question

Himpunan penyelesaian dari sistem persamaan a + 2b = 5 dan 2a – b = 5 adalah ...
a.
{(-3,1)}

b.
{(2,4)}

c.
{(1,-3)}

d.
{(3,1)}
​

Answer 1

Jawaban:

a + 2b = 5 |×2

2a - b = 5 |×1

2a + 4b = 10

2a - b = 5

__________ _

5b = 5

b = 1

a + 2b = 5

a + 2(1) = 5

a = 3

{3, 1}

Answer 2

D. {(5, 1)}

Penjelasan dengan langkah-langkah:

a + 2b = 5

a = 5 - 2b

2a – b = 5

2(5 - 2b) - b = 5

10 - 4b - b = 5

10 - 5b = 5

-5b = 5 - 10

-5b = -5

b = ,-5/(-5) = 1

a = 5 - 2b

= 5 - 2 x 1

= 5 - 2

= 3

HP = {(a, b)} = {(3, 1)}