Mathematics
Solve the following simultaneous linear equations:
ax + by = a - b
bx - ay = a + b
Answer
Given,
ax + by = a - b …….(i)
bx - ay = a + b …….(ii)
Multiplying eq. (i) by b and (ii) by a we get,
abx + b2y = ab - b2 ……(iii)
abx - a2y = a2 + ab …….(iv)
Subtracting eq. (iv) from (iii),
⇒ abx + b2y - (abx - a2y) = ab - b2 - (a2 + ab)
⇒ b2y + a2y = -b2 - a2
⇒ y(b2 + a2) = -(b2 + a2)
⇒ y = -1.
Substituting value of y in (i),
⇒ ax + b(-1) = a - b
⇒ ax - b = a - b
⇒ ax = a - b + b
⇒ ax = a
⇒ x = 1.
Hence, x = 1 and y = -1.