Question

b) 4x-3y=54 si x-y=12 ; c) x+y =16 si x>12​

Answer 1

b) 4x-3y=54
x-y=12 => x=12+y
=> 4(12+y)-3y=54
48+4y-3y=54
48+y=54
y=6
c) x+y=16 => x=16-y
x>12 => 16-y>12 => -y>-4 => y<4