Same question different answer options. Which expression is equivalent to c+c-7c?

7c 1-6c
-5c or c-6

What is the volume of the sphere shown below with a radius of 3?

What is the order of magnitude for the number of liters in a large bottle of soda served at a party

Me solve this problem, and someone clearly explain to me how to solve it.1.) use the value of the discriminant to determine if the given trinomials has 2 real solutions, 1 real solution, or no real solutions.a.  x2  − 4x  − 7 = 0b. 4r2  + 11r  − 3 = 0c. 3m2  + 7 = 0d.  t2  + 2t  + 1 = 0