Answer:
more than 200 calls
Suppose number of calls = x
According to plan 1: Total monthly charge is $24
According to plan 2: Fix charge is $16 and $0.04 per call
cost of x's call = $0.04x
and monthly charge according to plan 2 = 0.04x + 16
a) Plan 1 is more economical than plan 2.
0.04x + 16 > 24
solve it for x
.04x > 8
x > 200
b) So, if more than 200 calls are made then Plan 1 is more economical.
Step-by-step explanation:
Answer:
decimal: 0.4166666666...
fraction: 15/36 (simplified: 5/12)
Step-by-step explanation:
So to find the discriminant of a quadratic equation, the formula is b² - 4ac with a = x² coefficient, b = x coefficient, and c = constant. In this case, our equation is 
Firstly, solve the multiplications and the exponents: 
Next, subtract and we find that our discriminant is 0.
*Additional Info: Since the discriminant is zero, this means that this quadratic equation has 1 real solution.