Expanding along the first row

= x²(2×4 – 1×1) – x(0×4 – 1×3) + 1(0×1 – 2×3)

= x²(8 – 1) – x(0 – 3) + 1(0 – 6)

= 7x² + 3x –6

Also |A| = 28

⇒ 7x² + 3x – 6 =28

⇒ 7x² + 3x – 34 = 0

⇒ 7x² + 17x – 14x – 34 = 0

⇒ x(7x+ 17) – 2(7x +17) = 0

⇒ (x–2)(7x +17) = 0

Integer value of x is 2.