Question

How to eliminate this using multiplication?

Answer 1

-2a + 3b = 9 / x 2;

-4a + 6b = 18;

Then, -4a + 6b = 18
          +4a - 2b = 3 
          __________________(+)

We obtain 4b = 21;

b = 21/4;

-2a + 63/4 = 9;

-8a + 63 = 36;

-8a = - 27;

a = 27/8 ;