Solve the simultaneous equations by using Cramer's rule. 4x = y – 5 and y = 2x + 1.

Answer:

Let 4x – y = - 5  ------------------ eq. no. (1)

and – 2x + y = 1 ----------------- eq. no. (2)

∴ D = 4 - 1  = (4× 1) – (- 2×- 1) = 4 - 2 = 2 - 2   1 ∴ Dx = -5 -1 = (-5× 1) – (1× -1) = -5 + 1 = -4 1 1 ∴ Dy = 4 -5 = (4 × 1) – (-2 ×-5) = 4 – 10 = -6 -2 1 ∴ By Cramer's Rule x = Dx = -4 = -2 D 2 y = Dy = -6 = -3 D 2 Ans. x = -2 and y =  -3