Answer:
a = 1, b = 7
Explanation:
Given the 2 equations
3a + 6b = 45 → (1)
2a - 2b = - 12 → (2)
Multiply (2) by 3 and add to (1) to eliminate the term in b
6a - 6b = - 36 → (3)
Add (1) and (3) term by term
(3a + 6a) + (6b - 6b) = (45 - 36)
9a = 9 ( divide both sides by 9 )
a = 1
Substitute a = 1 in either (1) or (2) and solve for b
(1) → 3 + 6b = 45 ( subtract 3 from both sides )
6b = 42 ( divide both sides by 6 )
b = 7