Question

Persamaan 1/4x + 1/5y= 1/20 dan -3x-2x=1. berapa himpunan penyelesaiannya?

Answer 1

Verified answer

(1/4)x + (1/5)y = 1/20
kedua ruas dikali 20 agar memudahkan
20(1/4x + 1/5y) = 20(1/20)
5x + 4y = 1

5x + 4y = 1 (dikali 3)
-3x - 2y = 1 (dikali 5)

15x + 12y = 3
-15x - 10y = 5 +
---------------------
2y = 8
y = 8/2
y = 4

bila y = 4, maka x = ....
5x + 4y = 1
5x + 4(4) = 1
5x = 1 - 16
x = -15/5
x = -3

jadi x = -3, dan y = 4