Cosine law
a^2 = b^2 + c^2 - 2(b)(c)cosA
a^2 = 2^2 + 4^2 - 2(2)(4)cos78
a = 4.08
a = 4.1
<h2>
Answer:</h2>
This is a 2-step equation:

The solution is <em>x = 3</em>.
Answer:
Step-by-step explanation:
The angle opposite to longest side is the largest angle.
WY is the longest side. ∠x is the greatest
Arrange sides from largest to smallest
WY > YX > XW
∠X > ∠W > ∠Y
No solution since both variables cancel
160 = 2 x 2 x 2 x 2 x 2 x 5 = 2^5 x 5
243 = 3 x 3 x 3 x 3 x 3 = 3^5
So
(160 * 243)^1/5
= 5th root of (160 * 243)
= 5th root of (2^5 * 5 * 3^5)
= 2 * 3 * (5th root of 5)
= 6 * (5th root of 5)
Answer is D. 6 * (5th root of 5)