7x-6 greater than or equal to -3x^2 reduced and written in interval notation

Answer 1

7x - 6 ≤ - 3x^2
3x^2 + 7x - 6 ≤ 0
(x + 3)(3x - 2) ≤ 0

the zeros of the corresponding function are x = -3 and x = 2/3

so:
-3 ≤ x ≤ 2/3

convert to the notation that you use in your class, I prefer the notation I just used.