The product of the two numbers is 80. If one of the numbers is 4 times the other. Find both numbers.

AcademicMathematicsNCERTClass 8

Given:

The product of the two numbers is 80.

One of the numbers is 4 times the other.

To do:

We have to find both numbers.

Solution:

Let one number be $x$.

This implies,

The other number $=4\times x$

$=4x$

The product of the two numbers is 80.

This implies,

$x \times 4x=80$

$4x^2=80$

$x^2=\frac{80}{4}$

$x^2=20$

$x=\sqrt{20}$

$x=\sqrt{4\times5}$

$x=2\sqrt5$

$4x=4(2\sqrt5)=8\sqrt5$

Therefore, the required numbers are $2\sqrt5$ and $8\sqrt5$.    

raja
Updated on 10-Oct-2022 13:33:38

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