Answer:
a = 4 b = 5
Explanation:
8a + 12b = 92......eqn 1
6a - 4b = 4......eqn 2
multiply eqn 2 by 3
18a - 12b = 12.....eqn 2
add eqn 1 and 2 to eliminate b
26a = 104
a = 4
put a = 4 into eqn 2
18(4) - 12b = 12
72 - 12b = 12
72 - 12 = 12b
60 = 12b
5 = b