Answer:
x = 20
Step-by-step explanation:
Given the triangles are congruent then corresponding angles are congruent, so
∠ N = ∠ E
To calculate ∠ E subtract the sum of the 2 given angles from 180
∠ E = 180 - (x - 5 + 4x - 10)
= 180 - (5x - 15)
Equate ∠ N and ∠ E
5x - 5 = 180 - 5x + 15 ( add 5x to both sides )
10x - 5 = 195 ( add 5 to both sides )
10x = 200 ( divide both sides by 10 )
x = 20
is the only acute angle whose sin = 1/2. Therefore, cos (
) =
Given that we have the change in temperature over 7 hours and we are looking for the change over 1 hour, we can divide the total change in temperature by 7. Thus, the change in temperature would be 
.
Additionally, this can be solved by equations:
By using two different methods, we can determine that the change each hour was equal to 42/7 C° per hour.
4*5-3*4
20-12
=8
Just plug in the numbers and solve. Remember that you multiply before you subtract.
