Answer:
OPTION A
OPTION B
OPTION C
Step-by-step explanation:
Irrational numbers are the subset of real numbers. Their decimal representation neither form a pattern nor terminate.
OPTION A: 
This is equal to
.
is non-terminating. So, it is an irrational number. Hence, the reciprocal of an irrational number would also be irrational. So, OPTION A is irrational.
OPTION B: 
This is equal to
. Using the same logic as Option A, we regard OPTION B to be irrational as well.
OPTION C: 
This is equal to
.
Both
and
are irrational. So, the product and the reciprocal of the product is irrational as well. So, OPTION C is an irrational number.
OPTION D: 
16 is a perfect square and is a rational number.
=
. This is equal to 0.25, a terminating decimal. So, OPTION D is a rational number.
OPTION E: 
4 is a perfect square as well.
, a terminating decimal. So, OPTION E is a rational number.
The US postal service delivered 7.14 x 1010 pieces of mail in the month of December 7.14 x 1010=7211.4
3.21 x 1010 in the month of January. 3242.1
What is the total mail delivered for these two months?
7211.4
+ 3242.1
__________
10453 .5 TOTAL MAIL
Answer:
The solution to the system of equations is

Explanation:
Giving the system of equations:

To solve this, we need to first of all eliminate one variable from any two of the equations.
Subtracting (2) from twice of (1), we have:

Subtracting (3) from 3 times (1), we have

From (4) and (5), we can solve for y and z.
Subtract 5 times (5) from 3 times (4)

Using the value of z obtained in (5), we have

Using the values obtained for y and z in (1), we have
Get Y by itself so it' should look like this
5y=2x+7 after then you have divide 5 onto the right side and it should look like
Y=2/5x+7/5
Answer:
(-3, 7)
Step-by-step explanation:
It is like putting a mirror on the y-axis. It is asking what point is the photo negative of the point, like a mirror. You see yourself in the mirror but everything is opposite. Your right hand is your left. So which point is the photo negative of (3, 7)? (-3, 7) Because it is only across the y-axis, the y value stays the same.