Take some trinomial expansions to find some useful expressions and their values.
• 2nd degree expansion

• 3rd degree expansion

• 4th degree expansion

Simplify:



Then the equation we got from the 4th degree expansion reduces to

and all we need now is the value of
.
In the 3rd degree expansion, we have

So, we end up with

Step-by-step explanation:
add them by order to get the answer.
3x + 2y = 39
-3x -3x
2y = 39-3x
— ———
2 2
y= 19.5 - 3x/2
plug (19.5 - 3x/2) for y
1.5x - 2(19.5 - 3x/2)= 39
x= 17.33333333334
Answer:
40.5°
Step-by-step explanation:
The relevant trig relation is ...
Tan = Opposite/Adjacent
In this triangle, that means ...
tan(x°) = 4.7/5.5
The angle is found using the inverse function:
x° = arctan(4.7/5.5) ≈ 40.5°