Answer:
x-60
Step-by-step explanation:
You have to factor out the quadratic.
You know that one of the factors is x-40.
To factor:
Find a number that when added to -40, gives you -100, and also when multiplied, gives you 2400.
That such number is -60.
Add an x before it, and you get (x-60)
187.5
12 × 2.5 × 6.25 = 187.5
21 cm
To find the radius, half the diameter (42cm)
hope this helps :)
