Answer:
6x
Step-by-step explanation:
8x-2x
Step-by-step explanation:
z
3
=8(cos216
∘
+isin216
∘
)
z^3=2^3(\cos(6^3)^\circ+i\sin(6^3)^\circ)z
3
=2
3
(cos(6
3
)
∘
+isin(6
3
)
∘
)
\implies z=8^{1/3}\left(\cos\left(\dfrac{216+360k}3\right)^\circ+i\sin\left(\dfrac{216+360k}3\right)^\circ\right)⟹z=8
1/3
(cos(
3
216+360k
)
∘
+isin(
3
216+360k
)
∘
)
where k=0,1,2k=0,1,2 . So the third roots are
\begin{gathered}z=\begin{cases}2(\cos72^\circ+i\sin72^\circ)\\2(\cos192^\circ+i\sin192^\circ)\\2(\cos312^\circ+i\sin312^\circ)\end{cases}\end{gathered}
z=
⎩
⎪
⎪
⎨
⎪
⎪
⎧
2(cos72
∘
+isin72
∘
)
2(cos192
∘
+isin192
∘
)
2(cos312
∘
+isin312
∘
)
Answer:
9 mph
Step-by-step explanation:
Let Kathryn can go x mph and Stephanie can go (x + 5) mph.
Therefore, Kathryn can go 25.2 miles in hours.
And Stephanie can go 25.2 miles in hours.
Given that
⇒
⇒ 126 = x² + 5x
⇒ x² + 5x - 126 = 0
⇒ (x + 14)(x - 9) = 0
⇒ x = -14 or x = 9
But x can not be negative, so x = 9 mph
Therefore, Kathryn can ride her bike at 9 mph. (Answer)
Answer:
C =66
Step-by-step explanation:
Answer:
7,063
Step-by-step explanation:
90 × 78 + 53 − 20 ÷ 2 = 7,063