Question

Himpunan penyelesaian dari persamaan 2x+2/3 + 1/4y = 7 dan 3/4x-y-2/2= 3

Answer 1

2x + 2 1/4 y = 7 (dikalikan 12)
--------- +
3
= 4 (2x + 2) + 3y = 84
= 8x + 8 + 3y = 84
= 8x + 3y = 84 - 8
= 8x + 3y = 76 pers (1)

3/4 x - y - 2 = 3 (dikalikan 4)
--------
2
= 3x - 2(y - 2) = 12
= 3x - 2y + 4 = 12
= 3x - 2y = 12 - 4
= 3x - 2y = 8 pers (2)

》metode eliminasi pers 1 & 2
8x + 3y = 76 (dikali 2)
3x - 2y = 8 (dikali 3)
》16 x + 6y = 152
9x - 6 y = 24
-------------------------- +
25x = 176
x = 176 ÷ 25 = 7,04

》3x - 2y = 8
3(7,04) - 2y = 8
21,12 - 2y = 8
-2y = 8 - 21,12
-2y = -13,12
y = -13,12 ÷ -2
y = 6,56