math
posted by bill on .
1. x^2 + y^2 = 20
x+y=6
2. y=x^22x+1
y3=x
How would I go about solving these?

!. from the 2nd : y = 6x
sub into the 1st:
x^2 + (6x)^2 = 20
x^2 + 36  12x + x^2  20 = 0
2x^2  12x + 16 = 0
x^2  6x + 8 = 0
(x4)(x2) = 0
x = 4 or x = 2
2. from the 2nd: y = x+3
sub into the 2nd
proceed as above....
let me know what you got