Answer:
P(n,4)÷P(n,2)
= (n-2)(n-3)
20 = 4 × 5 (two consecutive numbers)
(n-2)(n-3)=5×4
n-2=5
n=7
Answer:
12
Step-by-step explanation:
Use the Pythagorean theorem which is a^2 + b^2 = c^2
c is hypotenuse and a and b are the legs
we need to find a^2 so
a^2 + 16^2 = 20^2
a^22 + 256 = 400
then subtract 256 from 400
a^2 = 144
square root 144
= 12
53-49=4
4 times 12=48. the unknown number is 48
