Question 698393
12n-5n=2n-7
7n=2n-7
7n-2n=-7
5n=-7
n=-7/5 ans.
proof:
12*-7/5-5*-7/5=2*-7/5-7
-84/5+35/5=-14/5-7
-49/5=-14/5-7
-49/5+14/5=-7
-35/5=-7
-7=-7