Answer:
5
Explanation:
this can be solved using simultaneous equation
2a + 3b = 19 equation 1
1a + 4b = 17 equation 2
Multiply equation 2 by 2
2a + 8b = 34 equation 3
Subtract equation 1 from 3
5b = 15
b = 3
Substitute for b in equation 1
2a + 3(3) = 19
2a = 9 = 19
2a = 10
a = 5