3x + 2y + 11 = 0; 7x – 4y = 9

(iv) 3x + 2y + 11 = 0; 7x – 4y = 9

Sol. 3x + 2y + 11 = 0

∴  3x + 2y = – 11

7x – 4y = 9

D	=	3	2	=	(3 × -4) – (7 × 2)	=	-12 – 14	=	-26
		7	-4

DX	=	-11	2	=	(-11 × -4) – (9 × 2)	=	44 – 18	=	26
		9	-4

DY	=	3	-11	=	(3 × 9) – (7 × -11)	=	27 + 77	=	104
		7	9

By Cramer's rule,

x	=	Dx	=	26	=	-1
		D		-26

y	=	Dx	=	104	=	-4
		D		-26

∴ x = – 1 and y = – 4 is the solution of given simultaneous equations.