Question

PLZ HELP ME !!!!
Which expressions below equal a rational number ? Choose ALL that apply !

Answer 1

(From top to bottom) wrong, right, right, right, wrong. This is because a irrational*an irrational number is rational, but a rational*an irrational is an irrational number

Answer 2

The correct option is are 2, 3 and 4.

Explanation:

Rational number: If a number can be defined in the form of p/q where, p and q are integers and q≠0, then it is known as rational numbers. For example: 0.2, 1/3 and 1 etc.

Irrational number: If a number can not be defined in the form of p/q where, p and q are integers and q≠0, then it is known as irrational numbers. For example: 0.222..., √2 and π etc.

`\pi√(36)=6\pi`

It is an irrational number because π is an irrational number.

`7√(5)-√(245)=7√(5)-7√(5)=0`

It is a rational number.

`(4)/(5)+(3)/(8)=(32+15)/(40)=(47)/(40)`

It is a rational number.

`(4√(7))(2√(7))=(4* 2)(√(7* 7))=8(7)=56`

It is a rational number.

`√(100)+√(5)=10+√(5)`

It is an irrational number because sum of a rational and an irrational number is always an irrational number.

Therefore the correct option is are 2, 3 and 4.