Step-by-step explanation:
Answer:
The two numbers are
518
694
Step-by-step explanation:
As per requirements the two equations will be
X+Y=1212
X-Y=518
When we subtract these equations we get
X=1212-518
X=694
Now put the X value and find the Y value in any equation
X+Y= 1212
Y=1212-X
Where X = 694
Y=1212-694
Y=518
X=694 and Y=518
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.
Answer: 0.5 oz is the weight of one cookie
Step-by-step explanation: If 2 cookies weight 1 oz then 1 cookie weights 0.5 oz.
