If the pattern continues in wich of the following years would the comet be visible again? a 2017d 2018c 2019 d 2020

2019 is the answer. The way to solve this is by taking 1956 and take away 1949 from it. You will get 7. Add 7 to 1956. You will get 1963, which is on the chart. Then add 7 to 1963 and you will get 1970, which is also on the chart. Then from that point on keep adding 7 to the year until you get one of the answers. Hope this helps! :3

Here is the order:

1949-1956-1963-1970-1977-1984-1991-1998-2005-2012-2019

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.