Since ∠2=60° = ∠8 so it will also be 60 °
the sum of the both are 60°+∠7=180°
∠7= 180°- 60° = 120°
Answer:
'∂' -- means a partial differential
'Δ' -- means a change in some variable.
'σ' --means 'sum' and 'deviation'.
The text says something about the world turning so maybe the equation has something to do with that? Maybe it is the equation for the earth's rotation. Sorry I can't find anything else, but I hope this helps a bit!
Look at the picture.
We have the equation (1) 12x + 4y = 40.
We know, the sum of the acute angles in a right triangle is 90°.
Therefore we have the equation (2) (12x + 4y) + (17x - y) = 90
Substitute (1) to (2):
40 + 17x - y = 90 <em>subtract 40 from both sides</em>
17x - y = 50 (3)
We have the system of equations:

Substitute the value of x to (3)

Answer: x = 3 and y = 1.
Answer:
There are 3 because 12 divided by 4 is 3.
Step-by-step explanation: