let the first number be X
and the second be Y
so 2x-y= -1 ---------(1)
2y+3x=9 ______(2)
solve the simultaneous eqn
from eqn (1) y= 2x+1 _____(3)
sub eqn (3) into eqn(2)
2{2x+1} +3x=9
4x+2+3x=9
7x=9-2=7
x=1
sub x=1 into eqn (3)
y=2(1)+1 = 2+1 =3
the two numbers are 1 & 3
