Answer:
3x=-y+12
2x+3y=-6
collecting the like terms we have
3x+y=12
2x+3y=-6
to solve this simultaneous equation, we use substitution method
we make y the subject in equation one:
y=12-3x
then we put y=12-3x into 2x-3y=-6 in equation two
2x+3(12-3x)=-6
2x+36-9x=-6
-7x+36=-6
-7x=-6-36
-7x=-42
x=-42÷-7
x=6
then we put x=6 in y=12-3x:
y=12-3x
y=12-3(6)
y=12-18
y=-6