Question

Jika x dan y adalah penyelesaian dari sistem persamaan 2x + 3y = 26 dan 3x + 4y = 37. Nilai 5x + 2y = ...

Answer 1

2x+3y=26 |x3| -> 6x+9y=78
3x+4y=37 |x2| -> 6x+8y=74

(6x+9y=78)-(6x+8y=74) = (y=4)

2x+3y=26
2x+3(4)=26
2x=26-12
2x=14
x=7

5x+2y= 5(7)+2(4)= 35+8= 43

jadi, 5x+2y=43.

Answer 2

2x + 3y = 26 | ×3 》 6x + 9y = 78
3x + 4y = 37 | × 2 》 6x + 8y = 74
___________________________________ -
0 + y = 4
y = 4

disubtitusikan ke

2x + 3y = 26
2x + 3.4 = 26
2x + 12 = 26
2x = 26 - 12
2x = 14
x = 14/2
x = 7


jadi :

5x + 2y
= 5.7 + 2.4
= 35 + 8
= 43