Answer:
26.4 is what i came up with if you divide im probably wrong sorry if i am
X⁴ - 81 = x⁴ - 9² (Difference of 2 squares, then we an write it:
(x²-3)(x²+3) =0, → then (x²-3) = 0 and (x²+3)=0
(x²-3) = 0 → x² = 3 → x = +√3 and x = -√3
(x²+3) =0 → x² = -3 → x = +√-3 and x = -√3→ or i√3 AND x = -i√3
A{ -3 , +3 , -i√3 , i√3}
Since the slopes are equal they are parallel. I hope this helps.
20× 8 = 160
160 + 2x > or = 500
-160--------------- -160
2x > or = 340
÷2------------÷2
x > or = 170
She has to sell at least 170 cupcakes to make $500 in profit.
Hope this helps!