Given two matrices are equal .i.e, A = B.

We know that if two matrices are equal then the elements of each matrices are also equal.

∴x + 10 = 3x + 4

⇒ x – 3x = 4 – 10

⇒ – 2x = – 6

⇒ x = 3 …… (1)

And y² + 2y = 3

⇒ y² + 2y – 3 = 0

⇒ y² + 3y – y – 3 = 0

⇒ y(y + 3) – 1(y + 3) = 0

⇒ (y + 3)(y – 1) = 0

⇒ y = – 3 or 1 …… (2)

And y² – 5y = – 4

⇒ y² – 5y + 4 = 0

⇒ y² – 4y – y + 4 = 0

⇒ y(y – 4) – 1(y – 4) = 0

⇒ (y – 4)(y – 1) = 0

⇒ y = 4 or 1 ……(3)

∴ The common value is x = 3 and y = 1