a = [2 3 4];
b = [3 5 2];
c = [1 1 1];

aplusb = a + b;
bplusa = b + a;
is_equal = (aplusb == bplusa)
is_equal_using_isequal = isequal(aplusb,bplusa)

aplusbandthenplusc = (a + b) + c;
aplusbplusc = a + (b + c);
is_equal = (aplusbandthenplusc == aplusbplusc)
is_equal_using_isequal = isequal(aplusbplusc, aplusbandthenplusc)