Question 715567
Given
(1) a + 9b = 3
(2) a + 4b = -2
Simply subtract (2) from (1) and get
(3) a - a + 9b - 4b = 3 -(-2) or
(4) 5b = 5 or
(5) b = 1
Put (5) into (1) and get
(6) a + 9*1 = 3 or
(7) a = 3 - 9 or
(8) a = -6
Let's check with (2).
Is (-6 + 4*1 = -2)?
Is (-6 + 4 = -2)?
Is (-2 = -2)? Yes
Answer: (a,b) = (-6,1).