2.2a + 3.4b = 1.2a + 2.6
Subtract 1.2a from both sides
2.2a + 3.4b - 1.2a = 1.2a + 2.6 - 1.2a
2.2a + 3.4b - 1.2a = 2.6
Add like terms:
(2.2a - 1.2a) + 3.4b = 2.6
a + 3.4b = 2.6
Subtract 3.4b from both sides:
a + 3.4b - 3.4b = 2.6 - 3.4b
a = 2.6 - 3.4b