SOLUTION: Does anyone know how to do this i need help. Use the substitution method to solve the system x^2+y^=20 x+y=1

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Does anyone know how to do this i need help. Use the substitution method to solve the system x^2+y^=20 x+y=1      Log On


   

Question 624570: Does anyone know how to do this i need help.
Use the substitution method to solve the system
x^2+y^=20
x+y=1
Answer by oscargut(2103) About Me  (Show Source):
You can put this solution on YOUR website!
x^2+y^2=20
x+y=1
Solution:
y = 1-x
x^2+(1-x)^2=20
2x^2-2x+1 = 20
2x^2-2x-19 = 0
x+=+%282+%2B-+sqrt%28+%28-2%29%5E2-4%2A2%2A%28-19%29+%29%29%2F%282%2A2%29+
x+=+%282+%2B-+2%2Asqrt%28+39+%29%29%2F4+
x+=+%281+%2B-+sqrt%28+39+%29%29%2F2+
if x+=+%281+%2B+sqrt%28+39+%29%29%2F2+ then y+=+%281+-+sqrt%28+39+%29%29%2F2+
if x+=+%281+-+sqrt%28+39+%29%29%2F2+ then y+=+%281+%2B+sqrt%28+39+%29%29%2F2+
Solutions:
x+=+%281+%2B+sqrt%28+39+%29%29%2F2+ , y+=+%281+-+sqrt%28+39+%29%29%2F2+
x+=+%281+-+sqrt%28+39+%29%29%2F2+ , y+=+%281+%2B+sqrt%28+39+%29%29%2F2+