C = 2 because 2 times 2 is 4 and 4+2 = 6
1) Rational numbers are the numbers which can be expressed as the fraction.
In mathematical form, you can say: anything like: p/q (where, q≠ 0)
2) An Irrational number is the number which can't be expressed in the form of fraction, it repeats upto infinite digits.
Hope this helps!
Step-by-step explanation:

y2 = y , x2 = 5
y1 = 2 , x1 = 3

-4 = y-2 ==> y = -2
Its an Integer. Integers include negative numbers, zero and positive numbers :)
<span>The diameter in centimeters (cm) of a human hair is about 0.0025 cm. In terms of scientific notation, it is written as 2.5 x 1</span><span>0^-3 cm</span>