Question 908037
4x-5y=11 and x^2+y^2=25

4x-5y=11
4x=5y+11
x=(5y+11)/4 




and x^2+y^2=25

((5y+11)/4)^2+y^2= 25

(5y+11)^2/16 +y^2=25

multiply equation by 15

(5y+11)^2+16y^2=16*25

25y^2+110y+121+16y^2=400

41y^2+110y-279=0
Find the roots of the equation by quadratic formula							
							
a=	41	,	b=	110	,	c=	-279
							
b^2-4ac=	12100	+	45756				
b^2-4ac=	57856						
{{{	sqrt(	57856	)=	240.53	}}}		
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}							
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}							
x1=(	-110	+	240.53	)/	82		
x1=	1.59						
{{{x2=(-b-sqrt(b^2-4ac))/(2a)}}}							
x2=(	-110	-240.53	) /	82			
x2=	-4.27						


y=1.59 OR -4.27


when y = 1.59
4x-5y=11
4x-7.95=11
4x=18.95
x=4.73
One pair of solution is (4.73 & 1.59)
Other pair you can work out 
using y=-4.27