Combinatorial Enumeration. That whole class was a rollercoaster ride of mind-blowing generating functions to prove crazy things. The exam had ridiculous questions like 'count the number of cactus trees with n vertices such that etc etc etc' and you'd do three pages of terrible terrible sums and algebra. Then your final answer would be something beautiful like n/2 and you'd breath a sigh of relief and thank the math gods.
Am i supposed to multiply? 5 times 3 equals 15
Triangle ABE is isosceles / Given
AB congruent to AE / Def isosceles
angle ABE congruent to angle AEB / Property of isosceles triangles
angle ABD congruent to angle AEC / Subst different name for same angles
BD congruent to EC / Given
triange ABD congruent to triange AEC / Side Angle Side
-x + 5y = 8
multiply this equation by 3
-3x + 15y = 24
now add it to the other equation ( elimination)
-3x + 15y = 24
3x + 7y = -2
-----------------------
0x + 22 y = 22
divide each side by 22
y =1
substitute into -x + 5y =8 to find x
-x + 5(1) = 8
-x + 5 = 8
-x =3
divide by -1
x =-3
Answer (-3,1)
Choice A
