I would say B , even though I’m only in 5 th grade
Step-by-step explanation:
f ( 4 ) = 64 + 32 - 64 - 32 = 0
Thus x - 4 is a factor
Find other factors by synthetic division.
"""""""|1"""""2""""- 16"""""-32
"""""4|"""""""4""""""24""""""32
"""""""|1"""""6"" """""8""""""0
( x - 4 ) ( x ² + 6x + 8 ) = 0
( x - 4 ) ( x + 4 ) ( x + 2 ) = 0
x = - 2 , x = - 4, x = 4
Answer:
The volume of the concentrated 80 gallons mixture is 20 gallons
The volume of water in the 80 gallons mixture is 60 gallons
Step-by-step explanation:
The given parameters are;
The content of Container A = The cleaner
The concentration of the cleaner = 20% solution
The content of Container B = Pure water
The concentration of the desired solution = 5%
The volume of the required solution = 80 gallons
Let x represent the volume of the concentrated solution and y represent the volume of water in the 80 gallons mixture
Therefore, we have;
20/100 × x + y×0 = 5/100×80
x + y = 80
y = 80 - x
20/100 × x + (80 - x)×0 = 5/100×80
0.2·x = 4
x = 4/0.2 = 20
x = 20 gallons
y = 80 - x = 80 - 20 = 60
y = 60 gallons
The volume of the concentrated solution (80 gallons mixture) = x = 20 gallons
The volume of water in the 80 gallons mixture = y = 60 gallons.
Answer:
Consider f: N → N defined by f(0)=0 and f(n)=n-1 for all n>0.
Step-by-step explanation:
First we will prove that f is surjective. Let y∈N be any natural number. Define x as the number x=y+1. Then x∈N, and f(x)=x-1=(y+1)-1=y. We conclude that f is surjective.
However, f is not injective. Take x1=0 and x2=1. Then x1≠x2 but f(x1)=0 and f(x2)=x2-1=1-1=0. We have shown that there are two natural numbers x1,x2 such that x1≠x2 but f(x1)=f(x2), that is, f is not injective.
Note:
If 0∉N in your definition of natural numbers, the same reasoning works with the function f: N → N defined by f(1)=1 and f(n)=n-1 for all n>1. The only difference is that you consider x1=1, x2=2 for the injectivity.
