Looks like the answer is 72.89 degrees, which is roughly equal to 73 degrees.
(b)
A polynomial has the form

± 
+ ....
the only expression fitting this description is : x² + 2x + 7
Multiply it by its self 3 times for example 2 to the square root of 3 2x2x2
First move the constant to the other side causing it to change sides
4x<-6-6
Then calculate the difference (-6-6)
4x<-12
Now divide both sides by 4
X<-3
Then you are left with your answer:
x<-3
Hope this helps! :3