Question 1032944

I am doing the substituttion method and I can't seem to find (a,b)
I would like it if you showed me step by step how you find the answer.
The question is 

a + 2b = 7 
2a = 3b
<pre>a + 2b = 7 ---- eq (i)
2a = 3b ------- eq (ii)
a = 7 - 2b
Substitute 7 - 2b for a in eq (ii) to find value of b
Substitute value of b into either equation to find value of a