Sagot :
2r + 3s= 9 <=> -6r -9s = -27;
3r + 2s= 12 <=> 6r + 4s = 24;
=> 0*r -5*s = -3 => s = 3/5;
2*r + 3*(3/5) = 9<=> 10*r + 9 = 45 <=> 10*r = 36 => r = 18/5;
3r + 2s= 12 <=> 6r + 4s = 24;
=> 0*r -5*s = -3 => s = 3/5;
2*r + 3*(3/5) = 9<=> 10*r + 9 = 45 <=> 10*r = 36 => r = 18/5;