jika x dan y adalah HP dari: x+1/2y= -4 x= 6-3y, maka nilai dari: x + 2y adalah..

jawab
x  + 1/2 y= = 4
x = 4 - 1/2 y
x = 6 - 3y
4- 1/2 y = 6 - 3y ||kali 2
8 - y = 12 - 6y
-y + 6y = 12 -  8
5y = 4
y = 4/5
x  = 6 - 3y → x = 6 - 3(4/5) = 6 - 12/5= 18/5
x+ 2y = 18/5 + 2(4/5) = 26/5