Question

QUIZ (1330)
Materi: SPLDV

Diketahui dua persamaan 5x + 6y = 83 dan 7x + 2y = 97. Maka nilai dari x - y adalah...
A. 19
B. 16
C. 13
D. 10​

Answer 1

Verified answer

Penjelasan dengan langkah-langkah:

SPLDV (eliminasi)

5x + 6y = 83

7x + 2y = 97

Eliminasi x

5x + 6y = 83|×7| 35x + 42y = 581

7x + 2y = 97|×5| 35x + 10y = 485

______________ _

+ 32y = 96

y = 96/32

y = 3

Eliminasi y

5x + 6y = 83|×1| 5x + 6y = 83

7x + 2y = 97|×3|21x + 6y = 291

_____________ _

-16x = -208

x = 208/16

x = 13

x - y

= 13 - 3

= 10 (opsi d)

Answer 2

Jawaban:

D. 10

Penjelasan dengan langkah-langkah:

5x + 6y = 83

7x + 2y = 97

nilai x:

5x + 6y = 83

6y = 83 - 5x __(÷ 3)

[tex]2y = \dfrac{83 - 5x}{3} [/tex]

Subtitusi:

7x + 2y = 97

[tex]7x + \dfrac{83 - 5x}{3} = 97[/tex]

[tex]\dfrac{21x}{3} + \dfrac{83 - 5x}{3} = 97[/tex]

[tex]21x + 83 - 5x = 291[/tex]

[tex]16x = 208[/tex]

[tex]x = 13[/tex]

Nilai y:

6y = 83 - 5x

6y = 83 - 5(13)

6y = 83 - 65

6y = 18

y = 3

Jadi,

x - y

= 13 - 3

= 10

Jawabannya D.