9) The solution of the equation a x + b y + 5 = 0 and b x - a y - 12 = 0 is
(2, -3)
Find the values of a and b.
Answers
Given :- The solution of the equation ax + by + 5 = 0 and bx - ay - 12 = 0 is (2, -3) .
To Find :-
- The values of a and b ?
Answer :-
putting values of x and y we get,
→ ax + by + 5 = 0
→ a * 2 + b * (-3) + 5 = 0
→ 2a - 3b + 5 = 0
→ 2a - 3b = (-5) ----------- Eqn.(1)
and,
→ bx - ay - 12 = 0
→ b * 2 - a * (-3) - 12 = 0
→ 2b + 3a - 12 = 0
→ 3a + 2b = 12 ----------- Eqn.(2)
multiply Eqn.(1) by 3 and Eqn.(2) by 2 and then subtracting the result we get,
→ 3(2a - 3b) - 2(3a + 2b) = 3(-5) - 2*12
→ 6a - 6a - 9b - 4b = - 15 - 24
→ - 13b = - 39
→ b = 3 (Ans.)
putting value of b in Eqn.(2) ,
→ 3a + 2 * 3 = 12
→ 3a + 6 = 12
→ 3a = 12 - 6
→ 3a = 6
→ a = 2 (Ans.)
Hence, value of a and b are 2 and 3 respectively .
Learn more :-
Subtract 5pq + 4 q2 – 3p2 from 6p2 + 2q2 – pq
https://brainly.in/question/37611750
Answer:
Find b by substituting it in equation 1 or 2
