Answer:
a = 3, b = - 1
Explanation:
Given the 2 equations
3a + 2b = 7 → (1)
a - 2b = 5 → (2)
Rearrange (2) expressing 2b in terms of a
2b = a - 5 ← Substitute into (1)
3a + a - 5 = 7
4a - 5 = 7 ( add 5 to both sides )
4a = 12 ( divide both sides by 4 )
a = 3
Substitute a = 3 into (1 ) or (2 ) for corresponding value of b
Using (1 )
9 + 2b = 7 ( subtract 9 from both sides )
2b = - 2 ( divide both sides by 2 )
b = - 1