Question 904769
let the numbers be x & y

I condition

(1/3)x+(1/4)y =18

II condition

x-y 26

(1/3)x+(1/4)y =18
LCM of the denominator is 12
multiply equation by 12

4x+3y=216

4	x	+	3	y	=	216	.............1	
								
1	x		-1	y	=	26	.............2	
Eliminate	y							
multiply (1)by		1						
Multiply (2) by		3						
4	x		3	y	=	216		
3	x		-3	y	=	78		
Add the two equations								
7	x				=	294		
/	7							
x	=	42      						
plug value of			x	in (1)				
4	x	+	3	y	=	216		
168		+	3	y	=	216		
			3	y	=	216		-168
			3	y	=	48		
				y	=	16