Question 987137
y=x^2 - 10
9x^2 - y^2=90

solve the system by the substitution method 
--------------
y=x^2 - 10 --> x^2 = y + 10
Sub for x^2 in the 2nd eqn.
9(y + 10) - y^2 = 90
9y - y^2 = 0
y = 0
y = 9
------
Sub for y in any eqn to find x.