HP50g or other: U. of Houston calc exams

[CR Haeger]

Its been a while, but I think you can reduce to the a terms as follows:

A. 2x -3y = 6 - 7a^2 Parabolic surface?
B. -3x + 5y = 7+ 2a Plane
C. 7x +11y = 4 - 6a Plane

B*7/3 +C:
-7x + (35/3)y = (49/3) + (14/3)a
+7x +11y = 4 - 6a
D. 0x +(68/3)y = (61/3) - (4/3)a

A + B*⅔::
+2x -3y = 6 - 7a^2
-2x (10/3)y = (14/3) +(4/3)a
E. 0x +(⅓)y = (32/3) -7a^2 +(4/3)a

D - 68*E:
(68/3)y = (61/3) - (4/3)a
(-68/3)y = (-68*32/3) -68*(-7a^2) +(-68*4/3)a
F. 0y = -705 +476a^2 -92a

Ti36x [poly solv] for the quadratic (F) yielded a = -1.123... or +1.317.... Back solving for x = 0.0214 and y = 0.963 for a=-1.123... If this is correct, Ill have a drink and if not, two.

I expect the 50g or Prime could make quick work of this.