Proposition 2.30. suppose x and y are topological spaces, and f : x → y is any map. (a) f is continuous if and only if f (a c f(a) for all asx. (b) f is closed if and only if f (a) 2 f(a) for all a cx. (c) f is continuous if and only if f -(int b) ) for all b cy. (d) f is open if and only if f-'(int b) 2 int f-'(b) for all b c y.

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

i would pic false cause it goes down towards negative

step-by-step explanation:

answer: 42

use a calculator to find that 845/73 = 11.575

the whole part of the answer is 11. multiply this by 73 to get 11*73 = 803.

subtract that result from 845 to get 845 - 803 = 42