We are to select 2 people to sit in first row from 6.
This is a problem of Combinations. We are find permutation of 6 people taken 2 at a time. This can be represented as 6C2.
So, the answer is option B
Answer:

Step-by-step explanation:
<u>Rational Numbers</u>
A rational number is any number that can be expressed as a fraction

for a and b any integer and b different from 0.
As a consequence, any number that cannot be expressed as a fraction or rational number is defined as an Irrational number.
Let's analyze each one of the given options

The first part of the number is indeed a rational number, but the second part is a square root whose result cannot be expressed as a rational, thus the number is not rational

The second part is an exact square root (resulting 4) but the first part is a known irrational number called pi. It's not possible to express pi as a fraction, thus the number is irrational

The square root of 121 is 11. It makes the whole number a sum of a rational number plus an integer, thus the given number is rational

As with the first number, the square root is not exact. The sum of a rational number plus an irrational number gives an irrational number.
Correct option:

Answer:
2x-y=0
x=1/2y
Step-by-step explanation:
2x=84 is a one step equation so all u need to do is divided both sides by 2 so the variable can be by itself, so x=42
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