Answer:
x= 1 and y= -4
Explanation:
3x-6y=27
3(x-2y)=27
divide both sides by 3
x-2y=9 ->eq 1
6x+9y=-30
3(2x+3y)=-30
divide both sides by 3
2x+3y=-10 ->eq 2
multiply eq 1 by 2
2x-4y=18 -> eq 3
now subtract eq 3 from eq 2
2x + 3y= -10
± 2x + 4y= ±18 (-4y becomes +4y after changing sign due to subtraction)
7y = -28
y = -4 by dividing 7 on both sides
put value of y in eq 1
x-2(-4)=9
x+8=9
x= 9 - 8
x= 1