Question

resolva o sistema:
5x-4y=-9
-2x+3y=12

ME AJUDEM

Answer 1

5x = -9+4y
x=-9+4y/5= -9+4.6/5= -9+24/5 = 15/5 => x=3

-2(-9+4y/5)+3y=12
(18-8y)/5+3y=12
(18-8y+3y=12)/5
18-8y+15y=60
7y=42
y=6

Answer 2

5x-4y=-9  MESMO QUE X=(4Y-9)/5
-2x+3y=12
-2((4Y-9)/5)+3y=12
(-8Y+18)/5+3y=12
-8Y/5+18/5+15y/5=60/5
7y/5=60/5-18/5
7y=(60/5-18/5)*5
7Y=42
Y=42/7
Y=6

X=(4(6)-9)/5
X=(24-9)/5
X=15/5
X=3