Yes you can use the discriminant of a quadratic/polynomial. For instance, if

there is one real root. If

there are two real roots and i

there are no real roots
The discriminant comes from the quadratic equation, which is the following.
What is the question you are trying to ask
Answer:
Ava is 10 years old
Step-by-step explanation:
Sara is 8
Sara=$8 per week for 12 weeks
$8×12 weeks=$96
Ava has $24 more than Sara
x*12=96$+$24
12x=120
x=120/12
x=10
Ava's age is 10
Cylinder (A):
-Surface area: adding all areas of all faces of the shape.
*10 x 6= 60m^3
*3.14 x 3^2 = 28.274 m^2. Then We times it by 2 since we have 2 circles. Which equals to 56.55m^2
Total surface area: 60 + 56.55 = 116.55m^2
-Volume: 3.14 x r^2 x h, then substitute.
*3.14 x 3^2 x 10 = 282.74m^3
(B):
-surface area:
*7 x 11= 77
*5 x 11 = 55
*11 x 11 = 121
*7 x 5 = 35/2 = 17.5 > then again we times it by 2 cuz we have 2 triangles. Which equals to 35.
Total surface area: 77 + 55 + 121 + 35 = 288 cm^2
-Volume:
*7 x 5 x 11 = 385 cm^3
Make sure to check the units!!!
Hope this helped :)