Nguyễn Mạnh Hùng 14/06 at 02:57
Suppose: If all 9 numbers is smaller or equal than 1
The sum of them is small or equal than 9
So at least one of them must be bigger than 1 to have the sum 10 :)
Given \(f\left(x\right)=ax^3+bx^2+cx+d\) with \(a\in Z+\). Known that \(f\left(5\right)-f\left(4\right)=2012\). Prove that \(f\left(7\right)-f\left(2\right)\) is not a prime number.
Dao Trong Luan Coodinator 09/06/2018 at 12:20
f(5) - f(4) = (a.53 + b.52 + c.5 + d) - (a.43 + b.42 + c.4 + d)
= (125a + 25b + 5c + d) - (64a + 16b + 4c + d)
= 61a + 9b + c
f(7) - f(2) = (a.73 + b.72 + c.7 + d) - (a.23 + b.22 + c.2 + d)
= (343a + 49b + 7c + d) - (8a + 4b + 2c + d)
= 335a + 45b + 5c \(⋮5\) (1)
Because a > 0
=> 61a + 9b + c < 335 + 45b + 5c
=> f(7) - f(2) > 2012 (2)
(1), (2) => f(7) - f(2) isn't a prime numberLê Quốc Trần Anh selected this answer.
Alexa has x apples and 4y oranges. If she has the same number of apples and oranges, what is the ratio of x to y? Express your answer as a common fraction.
There are 300 members of the eighth-grade class at Woodlawn Beach Middle School, of whom 28 have Mr. Jackson for Algebra 1. Two members of the eighth-grade class will be selected at random to represent the school at an upcoming event. What is the probability that neither of the students selected will be from Mr. Jackson’s Algebra 1 class? Express your answer as a decimal to the nearest hundredth.
Lê Quốc Trần Anh Coodinator 08/06/2018 at 07:11
Sorry Dao Trong Luan for the wrong title. Can you do it again?
If it's the last title, we have m = 1 and n big [unsolved]
Nguyễn Mạnh Hùng 14/06 at 08:13