Uh is there a picture cuz we can't know what's a vetex angle if we don't see a pic
The first thing we must do for this case is find the number of total guitarists.
We have then:

We now look for the relationship between the number of guitarists playing jazz alone to the total number of guitarists.
We have then:

Where,
x: number of guitarists playing jazz alone
From here, we clear the value of x.

Then, the number of guitarists who play classical solo is:

Answer:
30 guitarists play classical solos in the contest
Do you know how to solve this??
Answer:
7x^2 + 14x - 12
Step-by-step explanation:
Add like terms:
(4x + 8x - 5) + (3x2 + 6x - 7) becomes:
4x^2 + 8x - 5 or (grouping like terms in columns):
+ 3x^2 + 6x - 7
---------------------
7x^2 + 14x - 12