Please help asap 2. Write an expression for the amount of sales
tax charged, in dollars, on an item that costs
c dollars. Hint: An expression is a number
sentence without an equal sign. Use the
decimal form of the sales tax rate times c

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